The Steelers are considering signing former New England Patriot LB Tully Banta-Cain. One of the major upsides of Banta-Cain is his familiarity with the 3-4 defense, and the physical tools to play defensive end should Mike Tomlin install the 4-3.
When you think of the Patriots LB corp, you don't immediately think of Banta-Cain, but the 4-year veteran did play all 16 games for the Patriots last year, recording 43 tackles and a solid 5 1/2 sacks.
I did discover one downside to Tully-Cain (and this is a joke really): he is the cousin of former NBA player Rodney Rogers , one of the all-time great underachievers in NBA history :)
I hope the Steelers pull the trigger on Banta-Cain. He seems like he would be a good fit at OLB, he's in his physical prime, and he should come at a relatively reasonable price.