Denver Broncos quarterback Peyton Manning reportedly played the last month of the 2014 season and his side's divisional-round defeat to the Indianapolis Colts with a torn right quadriceps.
The 38-year-old sustained the injury in his side's win over the San Diego Chargers on December 14, in a match where he was forced off the field at the end of the second quarter, forcing backup Brock Osweiler into action.
Manning returned to that game but struggled to throw deep, and the problem plagued him for the rest of the campaign, including in his side's defeat to the Colts in their first playoff game, reports ESPN.
The five-time NFL MVP has refused to rule out retirement from the game and ending his 17-year career in the league.