Is Troy Polamalu a lock to play tomorrow ?

No player is ever a lock to play....you never know what will happen during warm-ups (tweaked hammy etc)

from IDP Game Breakdowns:
INJURY UPDATE: S Troy Polamalu (knee) participated fully in Friday practice and is listed as PROBABLE for this weeks game.

fwiw most players do play when they are listed as Probable but just a few weeks ago Justin Durant was listed as Probable and did NOT play.

He is supposed to play. I would check back when inactives are announced but I doubt he's inactive

He is active