San Francisco 49ers' NFL free-agent signings 2021: Trent Williams signs historic deal

NFL free agency is off and running, and we're keeping track of every major signing, trade and release of the 2021 offseason, with analysis from our NFL Nation reporters and grades from our experts. The new league year began March 17 at 4 p.m. ET, meaning free-agent signings can be made official after that. The first round of the 2021 NFL draft begins April 29 on ESPN.

The 49ers had the ultimate Super Bowl hangover in 2020, dropping to 6-10 as they dealt with an avalanche of injuries along the way. Now, coach Kyle Shanahan and general manager John Lynch enter a pivotal offseason in which they have a lot of difficult decisions to make and holes to fill with limited resources available to make it happen.

In addition, significant change is likely to come at quarterback one way or another, whether in the form of a change in the starter or, at minimum, in the backups to incumbent Jimmy Garoppolo.

Here's a breakdown of every 2021 NFL free-agent signing by the San Francisco 49ers, and how each will impact the upcoming season:

Trent Williams, offensive tackle

Williams and the 49ers reached a six-year, $138.06 million deal that will make him the highest-paid offensive lineman in NFL history. The deal has $55.1 million in guaranteed money and includes a $30.1 million signing bonus, sources told ESPN's Dianna Russini.

What it means: The 49ers had to keep Williams, especially after the first couple days of the early negotiating window eliminated what would have been most of the desirable backup plans. With Williams returning, the 49ers not only have the player they believe is the best left tackle in the game, they also have flexibility in the NFL draft. Had Williams departed, they likely would have had to spend an early pick on a left tackle to replace him. Instead, the Niners have their man and can focus on getting the best available player in the first round and rest easier knowing their blindside protector is in place for the long haul.

What's the risk: Williams will be 33 when next season starts and though he returned strong from a rare form of cancer after missing the 2019 season, he still has a history of nagging injuries. Williams hasn't played a full 16 games since 2013 and though he also hasn't missed more than six games in a season (save 2019), the 49ers are paying a premium here with the expectation Williams will be available.

Samson Ebukam, defensive end

The 49ers are adding the former Rams defensive lineman on a two-year deal.

What it means: The 49ers were hit hard by injury in a lot of places last year but edge rusher might have taken the biggest blows. They played most of the season without star pass-rushers Nick Bosa (knee) and Dee Ford (back). And with Kerry Hyder Jr. set for free agency, the Niners needed to bolster the depth here. In four seasons in Los Angeles, Ebukam had just 14 sacks but he never missed a game and had a career-high 12.7% pressure rate last year, which ranked 15th in the NFL among those with 150-plus pass rush snaps. This probably won't be the last addition the Niners make at the position this offseason but it's the type of relatively low cost, high upside addition they needed.

What's the risk: Ebukam's deal could be worth up to $13 million over two seasons, a relatively high price for the production they're getting and if he doesn't improve on those numbers in San Francisco, it might not be worth it. The other question is how Ebukam will transition to playing defensive end in a 4-3 base defense after spending so much time standing up as a 3-4 outside linebacker with the Rams.

Jason Verrett, cornerback

Verrett agreed on a one-year deal worth $5.5 million to return to the 49ers.

What it means: Verrett was another of the Niners' top four or so free-agent priorities and getting him back is particularly important because nearly all of the team's top corners are about to hit free agency. Verrett is now San Francisco's de facto No. 1 cornerback and gives the Niners some level of certainty at the position with Emmanuel Moseley also re-signing on the opposite side as a restricted free agent. The 49ers still need to add at the position but they can breathe just a bit easier about their cornerback position with Verrett back in the fold.

What's the risk: With Verrett, the risk is the same as it's always been: can he stay healthy? After playing just six games in a four-year span, Verrett bounced back in a big way last year, appearing in 13 contests and becoming the Niners' most consistent cornerback. Because it's just a one-year deal worth more than $5 million, there's not much financial risk but the Niners would be well-served to continue investing, be it money and/or draft capital, at cornerback in order to provide protection at an important position should Verrett have any more health issues.

Kyle Juszczyk, fullback

Juszczyk agreed to a five-year, $27 million deal that includes $10 million guaranteed

What it means: Juszczyk is one of about four Niners the team prioritized. That they were able to get a deal done before free agency began means they won't have to sweat it out as Juszczyk fields offers from other teams, particularly the New York Jets. With their versatile, valuable fullback in place, the Niners can continue to throw a variety of wrinkles at defenses out of similar personnel groupings.

What's the risk: While the Niners use Juszczyk as more than a standard lead-blocking fullback, five years and $27 million is a lot for a position many other teams don't employ at all and for someone who averaged 28.5 snaps per game last year. Also, Juszczyk will be 30 when the season starts and it's fair to wonder how much gas he has left in the tank. The Niners must find ways to use him more in the passing game to get maximum value.

K'Waun Williams, cornerback

K'Waun Williams is returning the 49ers on a one-year deal.

What it means: The 49ers managed to keep all of their top four in-house free agents as Williams joins left tackle Trent Williams, fullback Kyle Juszczyk and cornerback Jason Verrett in re-signing. That's significant if for no other reason than it allows the Niners plenty of flexibility when it comes to what they can do in the NFL draft. Williams is one of the league's top slot corners and beloved in the locker room for his fearless play and instincts.

What's the risk: Williams will be 30 when next season starts and he's coming off a season in which he played just eight games because of injuries. The Niners still don't have much depth at cornerback and would be wise to continue bargain shopping in free agency and add some young, cost controlled talent in the draft. After all, Verrett and Williams are on one-year deals and the Niners could use some long-term certainty in that group.

D.J. Jones, defensive tackle

What it means: The Niners set out to retain as many of their own free agents as possible and have been able to chip away at it in the early going of the new league year. Keeping Jones is a luxury for the Niners, who probably thought a starting caliber nose tackle like him might draw a bigger deal elsewhere. Instead, the Niners can now bring back all four members of their projected 2020 starting defensive line and Jones can take another shot at earning a bigger, long-term contract when the cap begins to rebound next year.

What's the risk: There's not much risk on a one-year deal for a player like Jones, who figures to be hungry to stay healthy and prove himself before hitting the open market again next year. The only thing that's seemingly held Jones back in his career is injury, as he has yet to play a full 16-game season because of various nagging ailments. Because of that and his pending return to free agency next year, the 49ers would be wise to continue developing in-house options at nose tackle and, potentially, finding some outside help capable of bolstering the depth chart.

Zach Kerr, defensive tackle

What it means: After bringing back starter D.J. Jones during the first week of free agency, the Niners continued to add some bulk to the middle of their defensive line by signing Kerr, who is 6-foot-2, 334 pounds, during Week 2. Kerr has bounced around the league a bit but does have 88 games of experience. He'll have a chance to compete for a couple of roster spots at nose tackle with Darrion Daniels and Jones.

What's the risk: Much like a handful of their other signings, this is a low-cost addition that bolsters the Niners' options and doesn't come with much risk. The bigger question is whether the 49ers have a long-term answer at nose tackle on the roster. Jones has a history of injury issues, Daniels is unproven and Kerr has been a journeyman. This isn't a position the Niners figure to make a big investment in but they'd probably like to have some stability here in the future.

Alex Mack, center

The 49ers signed Pro Bowl center Alex Mack to three-year deal.

What it means: It's no surprise but this signals the end of Weston Richburg's run with the 49ers after three injury-plagued seasons. Richburg could be set to retire but either way, Niners coach Kyle Shanahan has always emphasized the importance of a good center and Mack is one of his favorites. Shanahan and Mack worked together in Cleveland and Atlanta and Mack has ties to the Bay Area from his days at Cal, so this match always seemed possible, if not likely. Center was one more major offseason need for the 49ers but to land a member of the NFL's 2010s All Decade team at a reasonable price is a boon for an offensive line that needed help on the interior.

What's the risk: Mack is still a good player but he is 35 and closer to the end of his career than the beginning. Talented offensive linemen like him seem to have a longer shelf life these days so there still should be some gas in the tank but given the revolving door at center the Niners had last year, this isn't exactly a long-term solution. Which is why it would be wise for the 49ers to invest a draft pick into the position to begin grooming behind Mack.

Trent Sherfield, wide receiver

What it means: The Cardinals did not tender Sherfield, who was a restricted free agent, after three years as one of the team's primary special teams player. For the Niners, that's the role Sherfield, who made a reputation as a strong gunner on coverage units, will be expected to fill. The 49ers also have room for a receiver to elbow his way into playing time, especially in the slot, and Sherfield will get a shot to compete but special teams will be his path to a 53-man roster spot.

What's the risk: There really isn't much risk for a one-year, $920,000 signing. It does include $200,000 guaranteed, though, so if Sherfield doesn't make the roster that would be dead money on the cap for a team that figures to need every penny of space next season.

Dontae Johnson, cornerback

What it means: Nearly every 49ers cornerback who played significant snaps last year hit free agency in some form this week and the Niners have now managed to keep at least three of them, including Johnson. They re-signed Jason Verrett and Emmanuel Moseley, both of whom are expected to start, while Johnson will continue to give the Niners what he always has: reliable depth with special teams value. Johnson isn't suddenly going to emerge as a shutdown corner but he knows the system and the 49ers trust him in a pinch, which they clearly value.

What's the risk: There's not much risk in bringing back Johnson for depth, which is what this signing is all about. However, there would be plenty of it if the Niners don't continue to invest meaningful resources at corner. San Francisco still needs a nickel back and could use more starting caliber corners on the outside. They should continue to seek both in free agency and relatively early in the draft in order to mitigate that risk.

Jaquiski Tartt, safety

Jaquiski Tartt agreed to a one-year deal to remain with the 49ers.

What it means: The signing of Tavon Wilson didn't mean the end of Tartt's time in San Francisco, which is probably wise on the Niners' part, given the amount of injuries issued they've dealt with at safety in recent years. Tartt has proved a good player who is well-versed in the defense when healthy and he still has the ability to be a starter if he's ready to go.

What's the risk: With Tartt, the risk will always come back to health. He missed nine games last season with a toe injury, has never played a full 16-game season and hasn't appeared in more than 12 games since 2016. The good news for the Niners is they aren't leaving themselves without options as they have Tarvarius Moore, Marcell Harris and Wilson capable of competing with Tartt and it wouldn't be a surprise if they keep adding to their depth in the draft.

Tavon Wilson, safety

What it means: Wilson brings another veteran presence to San Francisco's secondary and offers more competition at strong safety along with Tarvarius Moore and Marcell Harris. Adding Wilson likely won't preclude the Niners from making additional moves at safety, as he's likely to battle for a spot on defense and special teams.

What's the risk: Like some of their other signings, there's not much risk in adding a player like Wilson on a low-cost, one-year deal. The bigger question is whether the Niners are as solid at strong safety as they think. Moore showed promise there at the end of last season but they don't have a lot of proven options, which means it wouldn't be a bad idea to add more in the draft.

Jordan Willis, defensive end

What it means: The 49ers traded for Willis in the middle of last season in hopes that giving him a chance to play edge rusher in a 4-3 defense would unlock the potential of the former third-round pick. Willis flashed at times, posting 13 tackles and 2.5 sacks in seven games. It was clearly enough to earn a longer look from the Niners and a full offseason and training camp should give him a chance to help as a situational pass-rusher for a team that believes you can never have too many of them.

What's the risk: It's a low-cost one-year deal that should be worthwhile for Willis to offer some depth on the edge, especially for a team that likes to rotate heavily on the defensive line. The real risk for the Niners would be if they don't continue to invest at this position given the uncertain status of Dee Ford. Adding Samson Ebukam and keeping Willis is a start but more help on the edge is still needed.

Mohamed Sanu, wide receiver

What it means: Wide receiver might have been the most under-the-radar need the 49ers had this offseason, especially after losing Kendrick Bourne. That's especially true in the slot, where Sanu is expected to get his opportunity to carve out a home. Sanu spent part of last season with the Niners and made a quick connection with some of the younger receivers, especially Brandon Aiyuk before he was released. Bringing him in to compete for a spot, see what he has left and offer some knowledge to the young receivers makes sense for the 49ers.

What's the risk: Sanu is 31 and coming off the second-least productive season of his career. While Sanu could still have some gas in the tank, the 49ers can't count on that, which means they still need to address the position further in free agency or, more likely, the draft. If they can find a slot receiver with some return skills in the middle rounds, they shouldn't hesitate to do it even with Sanu in the fold.

Nathan Gerry, linebacker

The 49ers signed linebacker Nathan Gerry to a one-year deal.

What it means: The 49ers have made a re-signing or addition at nearly every other position on the roster, so why not get in the mix at linebacker? In reality, the Niners are mostly set at linebacker, which is why they didn't make any big moves here. Instead, Gerry is their yearly attempt to add more depth and competition on special teams, as they've done in the past with signings like David Mayo and Joe Walker. If Gerry proves he can contribute on coverage units, he'll have a chance to stick on the 53-man roster.

What's the risk: Gerry signed a one-year, $990,000 contract with playing time incentives built in. There's almost no risk here, financial or otherwise considering what Gerry's role is expected to be. An argument could be made that the 49ers need better depth behind starters Fred Warner, Dre Greenlaw and Azeez Al-Shaair so if Gerry has to play, there could be some risk in not doing more to bolster the depth if the Niners don't invest a pick or two at the position in the draft.

Nate Sudfeld, quarterback

What it means: The 49ers' pursuit of a quarterback this offseason is finally over! OK, not really. But clearly the Niners still intend to improve the totality of the quarterback room, which is why they now have four quarterbacks -- Jimmy Garoppolo, Josh Johnson, Josh Rosen and Sudfeld -- under contract and another on the way with the No. 3 pick in the draft. Sudfeld is a candidate to compete with Rosen and Johnson for the third spot on the depth chart, though it seems unlikely the Niners would carry five quarterbacks through training camp. If Garoppolo ends up being traded, perhaps Sudfeld could work his way into the mix for the No. 2 job.

What's the risk: Sudfeld has only thrown 37 passes in his NFL career, which started in 2017. While it's unlikely Sudfeld will have to play in a game in 2021 (and he still has to win a roster spot first), it's fair to wonder whether the 49ers quarterback room will actually be better than it was last year. With the addition of a rookie taken at No. 3, it absolutely should. But that's not a guarantee, especially since a rookie might not have a full offseason to learn the offense and because of Garoppolo's injury history.