Tampa Bay Buccaneers defensive end Adrian Clayborn has been placed on season-ending injured reserve with a knee injury, the team announced Monday.

Rick Stroud of the Tampa Bay Times reported the second-year defender tore a ligament in his right kneeduring Sunday's loss to the Dallas Cowboys. The team hasn't confirmed if the tear was to Clayborn's anterior cruciate ligament, which would loom as a dire setback for a pass rusher whose bread and butter is earned surging off the edge.

Clayborn's absence leaves the Bucs thin along a line that might be forced into a scheme change. The Buccaneers' official site suggested a switch from the 4-3 alignment to a three-man front might emerge in the coming weeks.

Clayborn, the team's first-round pick in 2011, played all 16 games and recorded 7 ½ sacks as a rookie, the second-highest takedown total for a first-year player in team history.

Defensive tackle Gerald McCoy is going to see increased traffic and havoc from blockers on the inside starting in Week 4. Ends George Johnson and Daniel Te'o-Nesheim will see more snaps, too, but Clayborn won't be easy to replace in Tampa Bay.