Gross, who has started every game since coming to Carolina in 2003, was ruled out Friday by coach John Fox. Gross was knocked unconscious during last Sunday's win over Atlanta and did not practice all week.
Otah, who has a sprained right ankle, missed his third straight practice on Friday. Fox rarely starts players who have missed all week of practice.
"It's part of the game," Fox said. "We've dealt with it before and we will deal with it again."
Fox wouldn't identify their replacements, calling those game-time decisions. However, Jeremy Bridges, who has filled in twice this season when Otah went out, is expected to start at right tackle. He started 14 games at right tackle for the Panthers in 2006.
At left tackle, Frank Omiyale could make his first NFL start. Although he's been around the league for four years, Omiyale has been played in only one game and never taken a snap on the offensive line in a regular season.
"Whether it's Frank Omiyale or whoever, if you get that opportunity you need to make the most of it," Fox said. "I think Frank is prepared for that."
Fox could also shift Travelle Wharton to left tackle and start Geoff Hangartner at left guard. He did that last Sunday when Gross was injured.
Also Friday, cornerback Ken Lucas (ankle) and receiver Ryne Robinson (knee) practiced in full, but are questionable for Sunday.
Linebacker Na'il Diggs (illness) returned to practice Friday after sitting out Thursday.
Copyright 2008 by The Associated Press