Mahomes and Parsons Out? Stars Are Falling: Why Pro Sports Has an Injury Crisis

The last two weeks of December 2025 felt like a recurring nightmare for sports fans. On December 15, Kansas City Chiefs quarterback Patrick Mahomes went down with a torn ACL and LCL in his left knee during a loss to the Los Angeles Chargers. That same day, Green Bay Packers pass rusher Micah Parsons—fresh off a blockbuster trade from Dallas—suffered a non-contact ACL tear against the Denver Broncos. One week earlier, Indianapolis Colts quarterback Daniel Jones tore his Achilles tendon in a game against Jacksonville.

Three franchise players. Three season-ending injuries. Two weeks.

If it feels like elite athletes are breaking down at an alarming rate, that's because they are. And the problem extends far beyond football. The NBA just opened its 2025-26 season without multiple superstars: Tyrese Haliburton (Achilles), Jayson Tatum (Achilles), Damian Lillard (Achilles), and Kyrie Irving (ACL) are all sidelined with devastating lower-leg injuries. NBA Commissioner Adam Silver even convened a panel of experts to investigate, revealing that the league suffered seven Achilles tears in 2024-25—compared to zero the previous year under identical circumstances.

The question isn't whether there's an injury crisis in professional sports. The question is: why is this happening despite billions spent on medical technology, training, and prevention?

The Numbers Don't Lie: Injuries Are Rising

The data paints a troubling picture across multiple sports. In the NFL, ACL tears have been remarkably consistent—averaging 62 per season from 2015-2019, with a 1.9% annual risk for each player. But that consistency masks a deeper problem: the rate increased 49% during in-season play in the COVID-affected 2020 season, and recent weeks suggest the trend is accelerating.

The NBA's Achilles crisis is even more striking. Seven tears in one season represents a 75% increase over the previous record of four. These aren't random role players—we're talking about All-Stars and franchise cornerstones in their prime. Haliburton tore his Achilles in Game 7 of the NBA Finals at age 25. Tatum suffered his injury in the conference semifinals at 27, just one year after leading the Celtics to a championship.

Here's a snapshot of recent major injuries:

The Physics Problem No One Wants to Talk About

Here's the uncomfortable truth that emerged from research on this crisis: athletes are getting bigger and faster, but their ligaments aren't.

A groundbreaking insight from orthopedic surgeon Dr. Kevin Stone explains the core issue: When a six-foot-tall person increases their mass from 200 pounds to 350 pounds of muscle, their ACL doesn't grow proportionally. The ligament size is determined by the top of the tibia—meaning a 200-pound athlete and a 350-pound athlete of the same height have roughly the same size ACL.

Now add speed to the equation. A 350-pound NFL lineman in 2024 can run the 40-yard dash nearly as fast as sprinters did a decade ago. The force generated when that mass plants and cuts? Exponentially greater than what the human ACL evolved to handle.

Consider Mahomes' injury: he was rolling right, chased by defensive end Da'Shawn Hand, planted his left foot to throw the ball away, and his knee buckled. No contact. Just physics. His 230-pound frame, built with elite muscle mass, generated more torque than his ACL could withstand when he planted and twisted.

Parsons suffered an eerily similar fate—chasing Broncos quarterback Bo Nix, trying to cut on his left leg, immediately pulling up and grabbing his knee. The Penn State product had been one of the most explosive pass rushers in football, with 65 sacks in just 76 career games. That explosiveness comes at a cost.

The Achilles Paradox: Better Medicine, Worse Outcomes

Achilles injuries present a different but related problem. While ACL tears are often associated with cutting and pivoting, Achilles ruptures frequently occur during explosive movements—jumping, accelerating, decelerating.

Daniel Jones' injury perfectly illustrates the issue. The Duke product was already playing through a fractured fibula in his left leg when his right Achilles gave out on a non-contact play. He simply dropped back to pass, planted his foot, and the tendon snapped. Jones had been having the best season of his career—68.0% completion rate, career-high passer rating—but his body couldn't keep up with the demands.

The NBA's Achilles crisis is particularly concerning because basketball requires constant explosive movements. Research from the University of Delaware's Dr. Karin Gravare Silbernagel, who studies tendon injuries in elite athletes, found that even after successful surgery, many players return to the court but not to peak explosiveness or durability.

That tracking matches what we've seen. Damian Lillard and Tyrese Haliburton both tore their Achilles in the 2024 playoffs and aren't expected to return until the 2026-27 season—a full 12-18 months of recovery. Even when they do return, history suggests they may never regain their pre-injury burst.

Why Prevention Isn't Working

The frustrating reality is that despite massive investments in sports science, prevention methods have largely failed. Here's what doesn't work:

Knee braces: Multiple studies confirm they offer minimal protection against ACL tears. As Dr. Stone notes, there's no external brace that can control the motion of the femur on the tibia without being screwed directly into bone. Athletes have largely abandoned them except for temporary post-surgery use.

Strength training: NFL players are the strongest athletes in the world, yet they tear ACLs at alarming rates. Why? Because muscle strength doesn't scale proportionally with the forces generated by increased mass and speed. A 350-pound player's muscles might be twice as strong as a 200-pound player's, but the forces on their knee during cutting can be three or four times greater.

Neuromuscular training: While landing mechanics and movement patterns can help, they can't overcome the fundamental physics problem. Teaching an athlete to "land softly" helps, but it doesn't solve the issue of ligaments that haven't evolved to handle modern athletic demands.

The NFL saw this play out in the 2020 season. With limited training camps and preseason due to COVID-19, ACL injury rates spiked 49% during in-season play. Less preparation certainly contributed, but it also revealed how fragile the injury-prevention ecosystem really is.

The College Connection: Where Does It Start?

What's often overlooked is that this crisis doesn't begin in the pros—it starts in college and even high school. Young athletes now train year-round, often specializing in a single sport from an early age. This intense, repetitive stress on developing bodies may be setting them up for catastrophic injuries later.

Mahomes played at Texas Tech, where he threw for 5,052 yards and 41 touchdowns in his final season. That level of production requires tremendous arm strength and mobility—both of which depend on ligament integrity. By the time he reached the NFL at age 21, he'd already put massive stress on his body.

Parsons had a decorated career at Penn State, where he was a consensus All-American and the Big Ten Linebacker of the Year. His explosive first step and relentless motor made him a first-round pick, but also meant years of maximum-effort plays putting stress on his knees.

The NBA sees similar patterns. Players like Haliburton (Iowa State) and Tatum (Duke) were elite prospects who played at the highest levels from their teenage years. By the time they're in their mid-20s and hitting their athletic primes, they've accumulated a decade-plus of high-intensity basketball.

What Can Be Done?

The sobering answer is: not much, in the short term. The fundamental problem—that human ligaments haven't evolved to match modern athletic demands—isn't solvable with current technology.

Some potential approaches being discussed:

Load management: The NBA has embraced rest protocols for stars, though it remains controversial. The NFL's 17-game season (up from 16) has actually increased injury risk, not decreased it.

Better injury prediction: Advanced imaging and biomarker testing might identify athletes at higher risk before catastrophic injuries occur. But this raises ethical questions about who gets to play and who gets flagged as "injury-prone."

Rule changes: Could football reduce the physical toll with modified contact rules? Could the NBA shorten its 82-game season? Maybe, but these changes face massive financial and cultural resistance.

Surgical advances: Some researchers are exploring ligament augmentation or reinforcement procedures, but we're years away from anything viable for elite athletes.

The most promising long-term solution might be the most controversial: accepting that human bodies have limits, and that pushing beyond those limits comes with consequences. That means shorter careers, more rest, and perhaps accepting that the superhuman performances we've come to expect simply aren't sustainable.

The Human Cost

Lost in the statistics and physics discussions are the human stories. Mahomes, at 30, is facing a nine-month recovery that could cost him the start of the 2026 season. His Chiefs were eliminated from playoff contention for the first time in his career, ending a decade-long run of postseason appearances.

Parsons was supposed to be the centerpiece of Green Bay's defense after the Packers gave up two first-round picks and defensive tackle Kenny Clark to acquire him from Dallas. He lasted 14 games.

Jones was having his career renaissance in Indianapolis, proving all his doubters wrong after being cut by the Giants. He'll spend 2025 in rehab, hoping teams still believe in him when he's healthy again.

These aren't just statistics—they're careers, livelihoods, and dreams derailed by injuries that modern medicine still can't prevent or predict.

What Comes Next

As the NFL playoffs begin without Mahomes and the NBA season continues without half its stars, fans are left wondering how much worse this can get. The answer, based on current trends: probably worse before it gets better.

The forces driving this crisis—bigger athletes, faster play, longer seasons, year-round training—show no signs of reversing. If anything, they're accelerating. Each generation of athletes is stronger and more explosive than the last, but evolution hasn't caught up. The human ACL and Achilles tendon are the same structures they were 50 years ago, now being asked to handle forces they simply weren't designed for.

Until that fundamental mismatch is addressed—either through dramatic changes to how sports are played or genuine breakthroughs in injury prevention—expect to see more stars fall. The injury crisis isn't coming. It's already here.

SOURCES:

1. ESPN - Chiefs QB Patrick Mahomes suffered torn ACL in loss to Chargers - https://www.espn.com/nfl/story/_/id/47306436/patrick-mahomes-exits-knee-injury-chiefs-playoff-hopes-end
2. ESPN - Mahomes has surgery for torn ACL; LCL also repaired - https://www.espn.com/nfl/story/_/id/47320352/kansas-city-chiefs-qb-patrick-mahomes-undergoes-surgery-torn-acl-lcl
3. ESPN - Source: Packers' Micah Parsons believed to have torn ACL - https://www.espn.com/nfl/story/_/id/47308768/packers-lose-micah-parsons-christian-watson-injuries
4. ESPN - Colts QB Daniel Jones out for season with torn Achilles - https://www.espn.com/nfl/story/_/id/47236840/colts-qb-daniel-jones-suffers-achilles-injury-ruled-out
5. NBA.com - Injuries a talking point at NBA media days - https://www.nba.com/news/injuries-a-talking-point-at-nba-media-days
6. NBA.com - Mavericks' Kyrie Irving has successful surgery on torn ACL - https://www.nba.com/news/kyrie-irving-acl-surgery
7. Bleacher Report - Adam Silver Says NBA Looking Into Injury Causes After Haliburton, Tatum Achilles Tears - https://bleacherreport.com/articles/25216330-adam-silver-says-nba-looking-injury-causes-after-haliburton-tatum-achilles-tears
8. Stone Clinic - Why are ACL Injuries on the Rise in the NFL? - https://www.stoneclinic.com/blog/why-acl-injuries-rising
9. PMC - ACL Tears in the National Football League From 2013 to 2020 - https://pmc.ncbi.nlm.nih.gov/articles/PMC8873553/
10. PMC - Epidemiology of Anterior Cruciate Ligament Tears in the National Football League - https://pmc.ncbi.nlm.nih.gov/articles/PMC9310443/
11. Newswise - NBA Season Opens Without Several Stars Dealing with Lower Leg Injuries - https://www.newswise.com/articles/nba-season-opens-tonight-without-several-stars-dealing-with-lower-leg-injuries-they-may-never-return-to-their-peaks