The Tampa Bay Buccaneers have placed defensive end Adrian Clayborn on season-ending injured reserve because of a knee injury, the team announced Monday. Clayborn tore a ligament in his right knee during Sunday's loss to Dallas, according to the Tampa Bay Times, although the Bucs have not confirmed which ligament has been damaged. The Bucs' official website notes that Clayborn's absence may force the team to switch from a 4-3 alignment to a three-man front. Clayborn, the team's first-round pick in 2011, started all 16 games last season and had 7.5 sacks. He started the Bucs' first three games this season, but did not have any sacks.