Barnwell: The NFL-altering Andrew Luck retirement, and what comes next

Clark on Luck: 'Most shocked I've been on any news' (1:36)

Ryan Clark was stunned by Andrew Luck's decision to retire and describes the battle Luck must have had with the decision. (1:36)

It's not hyperbole: Andrew Luck's stunning decision to move on from the NFL is the most shocking retirement American pro sports has seen since Michael Jordan left the NBA in 1993. The circumstances are obviously different, and we've seen players such as Barry Sanders and Calvin Johnson leave the game earlier than anybody would have expected, but 29-year-old quarterbacks in the prime of their careers just don't get up and leave. This isn't just a franchise-altering decision. It alters the entire complexion of the NFL.

To put this in context, by Pro Football Reference's Approximate Value statistic, there have been two players in NFL history who have posted a better season in their final NFL campaign than the Indianapolis Colts quarterback and then retired by choice before turning 30. One is former Vikings running back Robert Smith, who ran for 1,521 yards at age 28 before moving on. The other is Jim Brown. No quarterback has made the Pro Bowl in a season during his 20s and then immediately retired since Johnny Lujack, and if that name doesn't ring a bell, it's because Lujack retired in 1952.

There are players who retired before turning 30 after serious injuries, and perhaps it's unfair to leave Luck out of that group. He played through a shoulder injury in 2015 and 2016 before missing all of the 2017 season after undergoing surgery, and while Luck was excellent upon his return in 2018, he has struggled with a calf injury all offseason. In both cases, the organization expected him to return in a matter of weeks. In both cases, again, Luck's body didn't respond the way either he or the team expected. He was facing down another uncertain rehabilitation of an injury that seemed to linger months after it should have gone away. Some players have bodies that tell them it's time to give up the game in their mid-30s. Luck's body gave way years earlier.

Even given the prospect of Luck missing regular-season action with an injury that had seemed to transform into a high ankle sprain, the Colts couldn't have expected that he would decide to leave the sport. Luck had talked about being scared of his future in football while recovering from that shoulder surgery in 2017, and every player deals with both mental and physical exhaustion from playing in the NFL, but few have the privilege and power to leave on their own terms. Luck had both and is moving on. The Colts now have to deal with the repercussions.

The post-Luck Colts

In the short term, the Colts are devastated by this decision. Even if you assumed Luck was going to miss the beginning of the regular season, Indy was still the favorite to win the AFC South and compete for a Super Bowl. After Luck's announcement, Caesars Sportsbook moved Indianapolis' odds of winning the Super Bowl from 12-1 to 30-1. The Colts have gone from favorites to win the AFC South at -135 (a 57.5% implied chance of winning the division) to underdogs at +210 (32.3%). Every likely AFC playoff contender and the three other teams in the AFC South benefit.

The Colts held out quarterback Jacoby Brissett from their preseason game against the Bears on Saturday night, and while it seemed like they were just protecting their potential Week 1 starter, the significance of his role with the team has become clear. Indy will move forward with the former backup to Tom Brady as the starting quarterback and either Chad Kelly or Phillip Walker as the backup. There is a paucity of veteran options available on the free-agent market, especially after Josh McCown unretired to sign a one-year deal with the Eagles.

The Colts could attempt to sign someone like Matt Cassel to back up Brissett. If they're unsure about Brissett or want to add another option, they could head to the trade market for someone like Ryan Fitzpatrick, Case Keenum or Nick Mullens, but their hopes for the season realistically now rest upon a quarterback who threw all of four passes behind Luck in 2018.

The Colts acquired the former third-round pick Brissett in a swap of likely cuts with the Patriots just before the 2017 season, sending Phillip Dorsett to New England in return. He quickly moved into the starting lineup for a Colts team that was realistically going nowhere in Chuck Pagano's final season at the helm and played the way you might expect a backup passer to perform. Brissett was surprisingly effective on deep passes, but given a porous offensive line and middling receivers, he completed just 58.8% of his passes and averaged 6.6 yards per attempt, both figures comfortably below league average.

Brissett threw just seven interceptions and added some value as a runner, but when you factor in his 10% sack rate and the generous game situations he usually worked under, the North Carolina State product posted a Total QBR of just 43.3 in 2017. That ranked 27th among 30 qualifying passers and placed him squarely between Jay Cutler and DeShone Kizer, neither of whom kept his starting job in 2018. Brissett performed admirably given that he was thrust under center for an NFL team eight days after being acquired -- and Indy reportedly refused to consider offseason trade talks for Brissett even when it had Luck back on the roster -- but Brissett's 2017 season offers the Colts more hope than proof.

There are reasons to think he will be better in his second go-round as the starter. For one, he won't be switching teams at the end of training camp and learning a new playbook on the fly. Brissett spent all of 2018 working underneath debuting head coach Frank Reich, who molded his scheme to take advantage of Luck's strengths. Indy wasn't quite able to do that for Brissett under Pagano. The Colts' new starter should have better coaching with Reich at the helm, and they still have a little over two weeks before their Week 1 trip to face the Chargers. Reich was unquestionably thinking about and beginning to prepare for what his offense might look like with Brissett as the starter, at least to begin the season. Now, those preparations will be permanent.

Indianapolis also has a much more effective offensive line than the one that struggled to protect Brissett in 2017, although it's also fair to pin some of the blame for those sacks on Brissett himself. In two starts and 55 pass attempts with the Patriots, Brissett was sacked on 9.8% of his dropbacks, a rate far higher than those of Brady (3.4%) and Jimmy Garoppolo (4.5%) over the same time frame. Reich will need to focus on getting the ball out of Brissett's hands quicker than in years past.

Independent of what happens in 2019, general manager Chris Ballard now unexpectedly faces the most important offseason of his career. Brissett will be a free agent. The Colts are in excellent cap shape, but they'll owe a total of $18.8 million in dead money for Luck, with $12.4 million due in 2019 and the remaining $6.4 million on their cap in 2020. In what was a surprise to some, Ballard didn't use the more than $100 million the Colts had in cap space this offseason to go on a spending spree, preferring to focus on the team's culture while staying selective with his signings. There's no way Ballard could have known what was going to happen next, obviously, but the Colts might have found it easier to attract top-level talent with Luck as their quarterback than they will with Brissett -- or someone else -- as their signal-caller.

The prospects of any team finding a quarterback in free agency are always slim. The pool theoretically includes Brady, Drew Brees and Philip Rivers, but it would be a true shock if any of those passers ever played a down for another organization. Both Marcus Mariota and Jameis Winston are projected to be free agents, although they'll be retained via the franchise tag or an extension if they impress this season. The third tier includes passers with various red flags, including Keenum, Teddy Bridgewater and Eli Manning.

Indy might also look toward the trade market. The Vikings will have one year left on Kirk Cousins' deal, and if they don't make the playoffs with their wildly expensive free-agent addition, Minnesota might prefer to keep the core of its team together by trading Cousins and drafting a quarterback. Likewise, if the 49ers are more impressed by Nick Mullens than Jimmy Garoppolo this season, they could choose to ship their own expensive passer off to Indianapolis.

If the Colts do struggle under Brissett, they may find an alternative path to a quarterback. No franchise has enjoyed the quarterback fruits of the draft for a longer, uninterrupted stretch of time than the Colts, who managed to come away with two franchise passers by timing their bad seasons impeccably.

After the 1996 season, Peyton Manning surprised the Jets by choosing to stay at Tennessee for his senior season. The Colts, who were a wild-card team in 1996, fell to 3-13 in 1997 and subsequently drafted Manning with the first overall pick in 1998. Likewise, despite the chances that the Panthers would have taken him with the first pick in the 2011 draft, Luck decided to pass on his draft eligibility and spend another year at Stanford. A 10-6 Colts team would have had no shot at Luck, but after Manning went down injured and Indy went 2-14, the team fell in prime position to draft Luck with the first pick of the 2012 draft.

I'm not suggesting that the Colts should tank -- I'm not sure it's a viable plan for any NFL team -- but the Colts just suffered a massive downgrade at quarterback and rode an antiquated Tampa 2 defense last season. With the emotional impact of the Luck retirement, it's not crazy to imagine them falling into the top five of the 2020 draft and having a shot at someone like Oregon's Justin Herbert, who also passed up a chance to enter the draft and instead chose to return to school for his senior season. (Tua Tagovailoa doesn't have quite the poetry of the Herbert story for the Colts, but he also is draft-eligible for the first time in 2020.)

The Colts looked incredibly well prepared for the future after making the playoffs in 2018 with Ballard, Reich and Luck as the core of their operations on and off the field. Two of those three pieces are still in place. From an organizational perspective, though, the Colts had the most important position in sports filled by a superstar with years left in his prime, and he's gone. I have more confidence in Ballard and Reich than I would in most coach-GM combinations, but the Colts have had a no-doubt solution at quarterback for 20 straight years. Now, there's just doubt.

The post-Luck NFL

Whenever a player retires prematurely in the NFL, given what we know about the dangers of playing football, there's understandably a conversation about whether it represents a trend. Given that there really aren't many comparables for Luck's decision historically, it's difficult to place his decision in line with the choices made by backs such as Robert Smith and Barry Sanders or more recent decisions made by Calvin Johnson or Chris Borland.

I think Luck is a unique player in many ways. Few players would brag about their Settlers of Catan skills, start a book club or splurge with the money from their contract extension to buy a robot pingpong machine. When Luck missed the 2017 season, he rehabbed in the Netherlands for months. He spent chunks of his childhood growing up in London and Frankfurt. We know more about quarterbacks and their habits than we do about players at other positions, but it's also clear that Luck has thought about his life outside of football during his career. He has every right to pursue those interests while still young.

The idea that Luck is somehow slacking off or taking the way easy out by giving up on his dream is low-rent talking-head trash, and it's not worth your time. If you feel that way, read about what Luck played through during the 2016 season or check what actual NFL ex-players have said about Luck's decision. The idea that he shouldn't be upset about his choice because he made just over $100 million as a pro quarterback should be ridiculous for obvious reasons -- Luck just devoted a decade of his life to a sport he no longer feels physically capable of playing -- but it does afford him the choice of avoiding another grueling rehabilitation period.

It's fair to mention that Luck is operating from a position of privilege in making this decision, although using that to imply his decision was easy is naive or disingenuous. It's easy to think about what the stars of the game make, but there are countless players every year on the fringes of rosters who play through pain and undergo surgeries to try to eke one more year out of their careers for far less money than Luck would have earned in 2019. Some of those players would likely choose to retire if they had Luck's career earnings to fall back upon. I bring that up not to imply that Luck's decision was tough, but instead to suggest that other players aren't likely to follow in his footsteps unless they have a similar nest egg. In a league that has repeatedly placed an importance on keeping quarterbacks healthy, that goes even further for signal-callers like Luck.

I hope Luck is at peace with a difficult decision. Selfishly, of course, I wish he was sticking around. I'll never forget the comeback Luck led against the Chiefs in the 2013 playoffs, leading a team that was down 38-10 in the third quarter to a 45-44 victory, with Luck throwing for 443 yards, four touchdowns, and even recovering a fumble for a 5-yard score. Luck was so good in close games that he seemed to break accepted conventions of analytics and managed to run three straight mediocre Colts teams to the playoffs to start his career. He was saddled for years with a general manager who failed on virtually every one of his major trades and draft picks after acquiring Luck and then blamed Luck's contract extension for his inability to improve the defense. I would have liked to have seen Luck behind his 2018 offensive line and with Reich and Ballard in charge from the first moment he joined the Colts.

If this is really it for Luck, the comparison that comes to mind isn't a football player. It's Mark Prior, the Chicago Cubs pitcher who was regarded to have perfect mechanics as he entered professional baseball. Prior shot through the minors in months, was up with the Cubs a year after being drafted, and was an instant star. The Cubs showed little concern with Prior, running him out for five 130-plus-pitch outings over his first two seasons in a sport that wasn't yet hyper-focused on pitch counts. He was on the mound for the Cubs during the fateful Steve Bartman moment in 2003, five outs away from the World Series, a 22-year-old seemingly in the first chapters of what would be a legendary career.

Instead, it was the peak. The Cubs lost the game and the series. Prior was never right again, as the "perfect mechanics" weren't enough to overcome his workload. (Prior himself will say his mechanics were never perfect.) His pitching declined and he missed time with injuries in both 2004 and 2005. After 43 dismal innings in 2006, a 25-year-old Prior hit the disabled list and never returned to the majors. He spent the next four years without pitching in organized baseball before returning to the minors and then retiring in 2013.

Likewise, if any quarterback was predestined to succeed, it seemed to be Andrew Luck. He grew up the son of a quarterback and played at Stanford for Jim Harbaugh. By the end of his redshirt freshman season at Stanford, there was chatter that Luck was a future first overall pick. When Luck finally did leave school two years later, he was the best quarterback prospect of his generation. There were no holes you could realistically poke in his profile. He had prototypical size and athleticism. He played in a pro scheme. He had elite arm strength and accuracy. There were no intangible concerns.

Luck was an immediate success, but for everything we knew and projected and hoped would come true, his body just couldn't hold up to the stress. Without a competent offensive line for years, he took too many hits early in his career and faced the repercussions earlier than most. In his hastily arranged farewell news conference Saturday night, Luck said that he had promised he wouldn't put himself through the strain of his 2017 rehab again if he was faced with a similar sort of inexplicably lingering injury. I'm happy he was able to live up to his promise.