San Diego Chargers wide receiver Keenan Allen had to be carted off the field with a knee injury in Sunday's season opener against the Kansas City Chiefs. On Monday, the injury was confirmed to be a season-ending torn ACL. The Chargers activated rookie pass rusher Joey Bosa to take Allen's place on the roster.
Allen went down while running a route and stayed down on the field, in what looked like obvious pain. When he was carted off, he was covering his face with his hand. The Chargers announced after halftime that Allen would not be returning to the game.
Allen was having a big day for the Chargers, who led 21-3 at the time of injury. Allen himself led the Chargers with six receptions for 63 yards, and was targeted seven times when he went down in the second quarter.
The Chargers spent a third-round pick on Allen in 2013 and he's been the team's top receiver ever since. Unfortunately, he hasn't played a full 16-game season since he was drafted, and missed half the season with a lacerated kidney last year.
Allen was well on his way to obliterating his previous career bests last year, as he had 725 yards and four touchdowns in eight games. His career best was his rookie year, when he had 1,046 yards and eight touchdowns in 15 games. There is still every reason to expect he can make a comeback.