Two of Pittsburgh's top three outside linebackers opened training camp on the Physically Unable to Perform list: James Harrison and Jason Worilds. In their stead, second-year pro Chris Carter has been running with the first team opposite former Pro Bowler LaMarr Woodley. But the depth chart after Carter? Sparse. So much so, in fact, that Stevenson Sylvester was taking reps at outside linebacker during practice Tuesday. Another inside backer, Mortty Ivy, was playing on the outside, too.

"Sly's a guy who's been around here and understands the defense," coach Mike Tomlin said. "We'll give him an opportunity to exhibit that.

"We're just trying to even the lines out, and sometimes someone else's misfortune -- whether it's Jason Worilds or James Harrison -- provides opportunities for others to show what they're capable of. Even if it's a position change. We like the work; (Sylvester) is open to it, so we'll continue to take a look."

Follow Steelers reporter Chris Adamski on Twitter @CBSSportsNFLPIT and @BuzzsawPGH.