Roethlisberger practiced all week after missing last Saturday's 27-0 win over the St. Louis Rams because of a high ankle sprain.
The injury occurred three weeks ago in a home win against the Browns, but he played the following Monday in San Francisco and threw three interceptions in a 20-3 loss.
Polamalu (knee) did not practice until Friday but is expected to start Sunday. Center Maurkice Pouncey missed the past two games with a high ankle sprain but said he's going to play.
The playoff-bound Steelers need a win and a Baltimore loss at Cincinnati to win the AFC North and earn a first-round bye.