The Steelers can point to a rush defense ranked 31st in the NFL as a source of their problems this season. But an inability to challenge the run masks that the Steelers are gambling more defensively in an effort to create turnovers and win field-position battles.

The defensive numbers aren't pretty: 29th in sacks (13), 27th in interceptions (four) and 28th in fumble recoveries (two). The Steelers have only one forced fumble; Tamba Hali of the Chiefs and Robert Quinn of the Rams have a league-high four.

“It's been a tough year overall,” safety Ryan Clark said before Wednesday's practice. “When you're stopping teams from running the ball in your base stuff, you don't have to get tricky. You don't have to put anyone in bad position, and guys on the back end can play the pass. With the run-stoppers we've had here in the past, people couldn't run no matter how many (defenders) we had in the box. Cornerbacks played pass, and safeties stayed deep.

“When you have problems stopping the run, other people come in and feel they have to do different things, and that's how you become susceptible to play-action passes. We have to tackle on the back side, and when you don't do that, you open up a can of worms.”

• Guard David DeCastro (ankle)practiced Wednesday and said he expects to play against Buffalo on Sunday at Heinz Field. DeCastro, who didn't play Sunday at New England, returns to challenge what he called “probably the best defensive line we've faced all year.” But the Bills are ranked 17th against the run, giving DeCastro hope the Steelers might be able to lean more on running back Le'Veon Bell.