LB James Harrison said he's a "game-time decision," and the Steelers officially list their Pro Bowler as questionable.
But Harrison is highly unlikely to play Sunday in the season opener against the Denver Broncos.
Harrison sat out practice for the second consecutive day Friday. The Steelers rarely dress players who cannot practice late in the week. Harrison has made it through only two practices all preseason for the Steelers, and both were in a limited capacity (Monday and Wednesday).
"A little swelling, nothing major, just more irritation, a little pain, more soft tissue that hasn't healed yet," Harrison said.
Harrison had a bad back early in the offseason but has been bothered by his left knee since training camp opened. He has minor surgery on it last month.
The Pittsburgh Post-Gazette reported Harrison will not play Sunday. The team won't say officially, but based on its past, it would be shocking of Harrison played.
Mendenhall officially doubtful: Unlike Harrison, RB Rashard Mendenhall did practice all week -- fully. But he is listed as doubtful for Sunday as he continues his recovery from a torn ACL sustained Jan. 1.
"Physically, I'm fine," Mendenhall said. "Stability is fine, I continue to grow in strength, the running and cutting and everything is fine, so I'm just going to take it day to day."
RB situation clarifies itself: Even with Mendenhall likely out, the Steelers' injury woes at running back brightened some with word that RBs Isaac Redman and Baron Batch practiced fully and felt good afterward on Friday.
Redman said his ankle "feels about 10 times better than it was in the beginning of the week," while Batch (groin) declared, "I should be good to go."
Redman and RB Jonathan Dwyer both indicated they will share carries against the Broncos. New Steelers OC Todd Haley has shown a tendency to have a running back-by-committee in the past.
"We've got a good corps of running backs that can make plays," Redman said. "Each guy, whoever it is -- me, Dwyer or (rookie RB Chris Rainey) -- who's out there right now, we can make pays."
Van Dyke added: The Steelers officially added CB DeMarcus Van Dyke to the roster Friday and created room on the roster by, as expected, placing rookie G David DeCastro on the Reserve/Injured; Designated for Return List.
The 6-1, 187-pound Van Dyke was a third-round pick by the Oakland Raiders last year out of the University of Miami. He appeared in 14 games last season, starting four.
DeCastro, the Steelers' first-round pick, sustained a knee injury in a preseason win at Buffalo Aug. 25. Due to the new NFL rule adopted last month, DeCastro will be eligible to return after spending at least eight weeks on IR.
Follow Steelers reporter Chris Adamski on Twitter @CBSSportsNFLPIT and @BuzzsawPGH.