From Mike McCarthy on Tuesday about injuries:
(Has anyone been ruled out for Thursday?)
Ruled out? Not yet. We’re going to give them all a chance to come back tomorrow.
Since Wednesday's practice wasn't open to the public, I've got no idea how it turned out. It's possible anyone and everyone could play on Thursday, except the three guys who haven't yet passed their physical. I wouldn't expect they'll be too aggressive about getting guys back on the field if they're concerned at all.
As far as the Colts go, Stampede Blue has a good rundown on the players who missed practice this week. Honestly I didn't recognize the names of five players listed. The big names that are not expected to play appear to be C Jeff Saturday and TE Dallas Clark.