Amid the handful of trades and dozens of free-agent signings that marked the beginning of the 2015 NFL league year yesterday, the three unexpected retirements of players in the primes of their careers seemed to fly underneath the radar. Patrick Willis was entrenched as the heart of San Francisco’s defense, while Jake Locker and Jason Worilds would have attracted interest from a number of teams. They chose to leave the game for different reasons, but the question will now naturally become whether their justifications will become a more frequent trend among professional football players who know the risks of their profession.

Each of the retirements was shocking in its own right, but it’s fair to start with Willis, the biggest name of the three. Physically, Willis had the most obvious link toward an uncertain future. He was ailing with foot pain, thanks to a toe injury that had been bothering him since college. Willis reaggravated the problem when he sprained the big toe on his left foot against the Rams in Week 6, an injury that seemed week-to-week before Willis chose to undergo corrective surgery. He suggested he was having the surgery to extend his football career, but months later, he appears to have had a change of heart.

He leaves the game as one of the most accomplished players of his generation, part of a 2007 draft class that includes Adrian Peterson, Calvin Johnson, and Darrelle Revis. The only player from that year to make as many Pro Bowls or be a first-team All-Pro as frequently as Willis through the end of the 2014 season was Browns tackle Joe Thomas. The Pro-Football-Reference.com statistic Approximate Value rates Willis as the best player of that draft class and as the second-best non-quarterback since he entered the league, behind only Saints guard Jahri Evans.

Arguments that Willis didn’t last long enough to be considered as a possible Hall of Fame candidate are bizarre and misguided. Willis’s only season outside of the Pro Bowl during his eight years in the league was in 2014, when he missed 10 games. The first half of his career came on a 49ers team that wasn’t very good, so it’s hardly as if he was making it to the Pro Bowl on scholarship or because of his team’s record.

Willis finishes with five first-team All-Pro nods. Of the 16 other linebackers who accomplished that feat, 12 made it to the Hall of Fame, and when Ray Lewis is eligible, he’ll make it 13. The only recent exception is Zach Thomas, and I suspect he’ll also make it someday. This isn’t creating an arbitrary, obtuse distinction and then lumping Willis in with a bunch of Hall of Famers he otherwise doesn’t match; All-Pro appearances are one of the best ways of judging what onlookers actually thought about a player at the end of a season, and just about everybody who was as good as Willis that frequently was a Hall of Famer.

Put it this way: Pretend Willis returned from his toe injury and wasn’t 100 percent. Maybe the 49ers see that in camp and rotate him with their three other inside linebackers before moving on after the season. Willis goes to Cleveland and spends three years as a competent inside linebacker there, he finishes up with a year under Bill Belichick in London, and then he retires with the same seven Pro Bowl appearances and five All-Pro berths. Is anyone really suggesting he’s not a Hall of Famer with that résumé? We’re saying that injuries sapped him, but the cumulative impact still points to Canton. Nobody doubted Barry Sanders’s Hall of Fame candidacy when he retired at 30. This is a player who was just as accomplished at a less visible position.

Furthermore, Willis made the players around him great. Some of that credit belongs to Justin Smith, who also appears to be heading toward retirement at the age of 35. First it was Takeo Spikes, who had been a 4-3 outside linebacker for nearly a decade before moving to San Francisco during Willis’s second year. Spikes played at a Pro Bowl–caliber level during his three seasons by the Bay before leaving for San Diego, where he was nondescript.

The 49ers replaced Spikes with NaVorro Bowman, a third-round pick out of Penn State who looked lost during an uneven rookie season. Once thrust into the starting lineup next to Willis, Bowman became a three-time All-Pro before suffering a serious knee injury in the 2013 NFC Championship Game and missing the entire 2014 campaign.

Willis and Bowman were at the core of that dominant 49ers defense in 2011 and 2012, the first two years of the Jim Harbaugh era. You would have forgiven 49ers fans for thinking it was the beginning of a dynasty, given the staggering amount of young talent they had on both sides of the ball and the incredible head coach they had taken from the college ranks. Most of that core, especially on defense, is already gone. Harbaugh left for Michigan. Vic Fangio, his defensive coordinator, was passed over as Harbaugh’s replacement and left for Chicago. And when you consider the guys who started the majority of games for those defenses, the drop-off has been stunningly quick. The only player who hasn’t retired, left the team, suffered a serious injury, or seen his star fall dramatically thanks to off-field incidents is Ahmad Brooks, who may be a cap casualty in the weeks to come:

Pos Player Since 2011-2012 DL Isaac Sopoaga Left as FA for Philadelphia, out of football DL Justin Smith Retired? DL Ray McDonald Released after multiple off-field incidents LB NaVorro Bowman Missed entire 2014 season after serious knee injury LB Patrick Willis Retired LB Aldon Smith Went to rehab in 2013, suspended for half of 2014 season LB Ahmad Brooks Still on team CB Carlos Rogers Released, spent 2014 with Raiders, currently free agent CB Tarell Brown Spent 2014 with Raiders, currently free agent S Dashon Goldson Enormous free-agent bust after leaving for Buccaneers S Donte Whitner Signed with Browns in free agency

The 49ers have major holes elsewhere on the roster, but they’re about as well equipped as any team could be for losing a Hall of Famer in the prime of his career. They should be able to bring back Bowman, who turns 27 this month, and even if he isn’t the same player he was next to Willis before the knee injury, he should still be an effective starter. He’ll be joined by Chris Borland, a Thomas clone who came into the lineup for Willis and exhibited preternatural instincts as a run-stopper before going down with an ankle injury in December.

They even have a solid backup in Michael Wilhoite, who started all 16 games in Bowman’s place last year and was on the trade block before Willis’s retirement. San Francisco will also save nearly $7.5 million on its 2015 cap as a result of the decision, although I’m sure it would much prefer to pay the money and have its defensive leader back for another season.

Clean Out the Locker

Former Titans quarterback Jake Locker was in an entirely different position when he announced his retirement later Tuesday afternoon. Locker was a free agent after playing out his four-year rookie deal with Tennessee, and while he had failed to live up to the expectations Titans fans had after he was selected in the first round of the 2010 draft, there was little doubt that a 26-year-old quarterback with Locker’s athletic ability would find a backup job somewhere around the league.

Instead, Locker decided to bring a career riddled with injuries to its end. Locker came out of college as a classic tools-over-skills prospect, a quarterback with ridiculous arm strength, athleticism, and intangibles who struggled to read defenses and had major accuracy issues during his time at Washington. His 54.0 percent completion percentage in college pointed to a passer who would need to take major steps forward to succeed as a professional quarterback, and whether it was something innate, the injuries, or a lack of effective coaching, Locker managed to complete only 57.5 percent of his NFL throws.

Locker flips the typical narrative in other ways. Bleacher Report’s Matt Miller noted after the news that his pre-draft scouting on Locker included a quote from a Washington coach doubting Locker’s love of the sport, which seems odd for a player who was otherwise regarded as a passionate leader. Locker’s abilities as a high school baseball player led the Angels to draft him in the 10th round of the 2009 amateur draft, which has led to speculation that he might pursue a career in baseball, but the Angels reportedly aren’t interested in developing the 26-year-old despite originally giving him a $300,000 bonus. After missing nearly half of his professional career with injuries, Locker might just prefer to go home and move on.

Out of This Worilds

The third retirement might have been the strangest of all. Steelers outside linebacker Jason Worilds had no history of serious injuries — his wrist and hamstring problems from several years ago were considered relatively light issues by NFL standards. He was an ascending player, having accrued 15.5 sacks over the last two seasons as one of the few bright spots in a decaying Pittsburgh defense. Having just turned 27 last week, Worilds was hitting free agency as one of the league’s most valuable commodities, a young pass-rusher. Given interest from desperate teams like Tennessee and Philadelphia, it’s not out of the question to imagine Worilds making $20 million in guaranteed money on his next deal.

Instead, Worilds decided he wanted to move on from football. There was no “spiritual awakening” in the same way that Willis’s retirement has been linked to an increased focus on religion. Worilds wasn’t beaten down or beaten up. He’s not leaving for another sport, at least to the best of my knowledge. He’s leaving, presumably, because he can.

That’s the part that stands out to me. When we ask why Worilds is retiring, isn’t the opposing question — why stick around — just as relevant? Most people assume that players are going to play for as long as possible to try to earn as much as they can, but Worilds made $13.6 million from his four-year rookie contract and his season as Pittsburgh’s transition player. Locker finished his NFL career with $12.6 million in earnings. Willis, a superstar who made it to a lucrative contract extension, leaves having earned $42.6 million. They’re each vested in the NFL’s pension plan. It’s not obvious that these guys need more money.

And then there’s the elephant in the room. Players are more aware of the physical damage that comes with playing football than ever before. They still make shortsighted, self-endangering decisions like Julian Edelman did in the Super Bowl, but it would be impossible to imagine that players aren’t at least thinking about retiring earlier than they have in the past, or that their logic might be shifting from getting as much as possible for as long as possible to getting enough before getting out.

While I don’t pretend to believe for a second that the NFL truly cares about player safety, the idea of a league in which players are retiring younger would also appeal to the shield. It would replace veterans with younger players, driving down salaries under the league’s CBA. It would also replace experienced players with years of injuries from playing at the highest level with rookies who haven’t had the same wear and tear, reducing medical costs. I doubt the league will actually incentivize early retirements, but it could be best for all parties involved.

This could just be a blip. Jim Brown was followed by Sanders, who was followed by Robert Smith, but that’s only three running backs retiring relatively young across 35 years of players suiting up until the league didn’t want them anymore. Willis is the most recent player of that caliber to leave this early in his career. The vast majority of players aren’t going to leave $20 million on the table like Worilds probably did. Players like Tom Brady are lionized when they want to play until they’re 45. Jake Locker gets yelled at by idiots on Twitter.

I don’t think you’re going to see a dozen more players unexpectedly retire over the next two months. But viewed over a longer time span? It would hardly be a surprise to see players begin to retire earlier than they have in years past. The players of 2030 will probably have shorter careers than the guys who were drafted in 2010. It remains to be seen, though, whether those careers will be shorter by choice.