Football rapidly ages its players. By the time one has reached an elite level, their body has already undergone an incredible amount of strain. On average, players retire from the contact sport at the age of 35, with the average career span of eight years. If you enter the league with lingering injuries or get injured throughout your career, however, that number can drop and the span can shorten.

The latter is what has happened to running back Knowshon Moreno. According to The Washington Post, Moreno seems to be hanging up his cleats at the age of 28. The free agent missed the entire 2015 season with a bad knee, and with his stock value decreasing, teams continue to show little interest in the player.

“His knees needed a full year off last year to regenerate” Mike Klis of 9 News in Denver wrote. “He’ll be 29 in July and he didn’t have good speed to begin with. Mentally, Knowshon is 80 percent done, but he’s staying in great shape just in case.”

Moreno’s career had a history of injuries that kept him from playing, which we’ve seen in 27-year-old recently retired Percy Harvin, a sad but familiar story.

Drafted by the Denver Broncos in 2009, a torn anterior cruciate ligament in 2011, Moreno played a final season in Miami. That was cut short by injury in 2014 after playing only one full game—the 2014 season opener. He dislocated his elbow early in Week 2 and tore his ACL during the third quarter of his return a month later.

Moreno has run for 3,3616 yards and 27 touchdowns during his six-year NFL career.