Stinnie will be out of action for the next two years after he tore his knee in Saturday's game.
After Ali Marpet unexpectedly retired, Stinnie was in the running for the starting left guard job.
He got rolled up on when Adrian Colbert went to tackle him in the second half of the game. Stinnie was taken off the field in a cart.
The competition for the left guard position is likely to come down to two rookies, one who is making the transition from college to the pros and the other who started a game last season.
It has been a tough training camp for the offensive line, which is still adjusting to the loss of Marpet and Alex.
Pro Bowl center Ryan Jensen will be out for an extended period of time after he injured his knee on the third day of training camp.