I don't know that there's anything wrong with him physically, Cowher has simply had him inactive all year and has gone w/ Parker, Haynes, and now Davenport.
I've been wondering about this situation for a while, because I can't imagine someone w/ Staley's pride taking this very well for very long. I'd take him over Antowain Smith with all other things being equal, especially health.
Speaking of Antowain, wasn't his workout supposed to be today (even though most are scheduled for Tuesdays, when the players are off)?