Steelers coach Mike Tomlin said on Tuesday that Charlie Batch is scheduled to start Sunday's game.
Roethlisberger, who has missed the last three games with rib and shoulder injuries, has a chance to prove he is ready to play.
"Ben is getting closer to healthy," Tomlin said. "He threw (Monday) and I guess it could be described as successfully. We'll see what it looks like on the football field (Wednesday). He will be given an opportunity to prove that he is healthy and we will let that progress go from there."
The Steelers dropped their first two games without Roethlisberger in the lineup, but bounced back with a win at Baltimore on Sunday.
Tomlin also said that cornerback Ike Taylor could miss several weeks with a fractured right ankle. Cortez Allen will start in his place.
In addition, offensive tackle Mike Adams (ankle) will miss Sunday's game. Guard Willie Colon is expected to return against the Chargers after missing the last two games with a knee injury.
