PITTSBURGH — The Pittsburgh Steelers believe they have plenty of depth along the defensive line.

It will be tested after the team placed veteran defensive end Stephon Tuitt on the injured reserve/return list.

Defensive coordinator Keith Butler said Wednesday that Tuitt is dealing with a knee injury but did not get into specifics about the severity of the issue. Butler did confirm it’s one of the reasons why Tuitt did not practice during training camp.