http://www.pittsburghlive.com/x/pittsburghtrib/sports/steelers/s_558946.html
McFarland is stopping by as a FA, and a few more prospects: Jerod Mayo, Shawn Crable, Ryan Torain.
The Colts cut McFarland, so I doubt he has much left (the Colts don't exactly have a stable of good DT's), but if he can pass a physical, I wouldn't complain about the depth. He's probably better than Kirschke, and he'll probably sign for very little, considering he's another Tomlin guy and isn't exactly coveted around the league.
I think Crable would be a good pick, but I don't know about Mayo. We need a SILB, but Mayo's knock is that he can't take on blocks. He looks like another Timmons. I don't know anything about Torain.