Grading Bills in free agency: Breaking the bank on Star Lotulelei to help run defense

A breakdown of the initial wave of free agency for the Buffalo Bills:

Overall grade: B-plus. Of the $50 million the Bills guaranteed to players they signed or re-signed, $43 million was paid to players who are 28 or younger and reaching free agency for the first time. Although the positions and players on which the Bills spent the money can be debated, it was an ideal approach that could help address what was an aging roster in 2017.

Most significant signing: In terms of financial investment, the headline signing of free agency was defensive tackle Star Lotulelei. Ranked No. 11 among ESPN's top 100 free agents, Lotulelei joined Buffalo on a five-year, $50 million deal with $25 million guaranteed after five seasons with the Carolina Panthers. At $10 million per season, his deal becomes the richest among any player under contract for the Bills after the trades of left tackle Cordy Glenn and quarterback Tyrod Taylor. He is expected to fill the run-stuffing role vacated when the Bills traded Marcell Dareus last season. Adolphus Washington started in Dareus' place the final two months of the season and the results were subpar, with Buffalo allowing the NFL's second-highest average yards per rush inside the tackles, according to ESPN Stats & Information. If Lotulelei can help turn that around, he will be worth it.

Most significant loss: The Bills were interested in re-signing starting middle linebacker Preston Brown but clearly did not see him as a player they were willing to extend financially. Brown signed a one-year, $4 million contract with the Cincinnati Bengals that fell considerably short of other free-agent linebacker deals, including the one the Chiefs gave Anthony Hitchens ($9 million per season) and the Jets gave Avery Williamson ($7.5 million per season). No matter Brown's apparent limitations, he was one of the Bills' most reliable players during the past four seasons. He played at least 98 percent of defensive snaps and has worn the defense's radio-equipped helmet since his rookie season in 2014. The Bills do not have a natural replacement for Brown on the roster and must find a middle linebacker to direct their defense.

Player they should have signed: Quarterback Josh McCown. The Bills were "seriously interested" in McCown, TheMMQB.com reported, before he signed a one-year, $10 million contract with $5 million guaranteed to remain with the Jets. Instead, the Bills signed AJ McCarron to a two-year, $10 million deal with $6 million guaranteed. General manager Brandon Beane said he took a "methodical" approach to the free-agent quarterback market, essentially letting McCarron fall to Buffalo at a bargain price. That was a win for the Bills, as McCarron offered more upside than most of the more established veterans available. However, signing McCown would have also made sense. He is 38, has started 73 games, has been in the NFL since 2002 and is known as a valuable presence in the locker room. Between McCarron, 27, and Nathan Peterman, 23, the Bills have only five games of NFL starting experience at quarterback -- and could add a rookie to their room after April's draft. While the Bills needed to get younger across their roster, quarterback is a position where having a player of McCown's age and experience could have been helpful. Quarterbacks coach David Culley has coached in the NFL since 1994, but last season was his first specifically coaching quarterbacks.

Additions: Lotulelei, defensive tackle; Trent Murphy, defensive end; McCarron, quarterback; Vontae Davis, cornerback; Chris Ivory, running back; Russell Bodine, center; Marshall Newhouse, offensive tackle; Rafael Bush, safety; Julian Stanford, linebacker; Phillip Gaines, cornerback; Kaelin Clay, wide receiver.

Subtractions: Brown, linebacker; E.J. Gaines, cornerback; Deonte Thompson, wide receiver; Shareece Wright, cornerback; Seantrel Henderson, offensive tackle.

What’s next: Four of the Bills' free-agent signings -- Lotulelei, Murphy, McCarron and Davis -- rank within the top eight richest contracts on the team, which has depleted available funds to sign other free agents. The Bills have about $16 million in salary-cap room, a large chunk of which will be spent on rookies and otherwise used for emergency signings during the season. That leaves deals at or near the minimum salary to fill other spots, most notably wide receiver. The Bills showed interest in bringing back Thompson before he signed with the Dallas Cowboys, and the team could still use a speed threat to play a role alongside assumed starters Kelvin Benjamin and Zay Jones. Middle linebacker is also an area of need, with the Bills having hosted Will Compton, Kevin Minter and Karlos Dansby on free-agent visits since losing Brown.