He sustained multiple injuries in Monday night's game against the Kansas City Chiefs and his return could be weeks away, the Pittsburgh Post-Gazette reported
Roethlisberger injured his shoulder when he was sacked by Justin Houston and Tamba Hali in the third quarter, but, more critically, the same play also dislocated a rib in such a way that serious complications could result if the rib was pressed against his aorta.
There is no timetable for his return but Roethlisberger said he did not think his season was over.
Byron Leftwich will fill in for Roethlisberger.
Coach Mike Tomlin Tuesday described the injury to Roethlisberger's right shoulder as a sprain to the sternoclavicular joint, which connects the sternum to the collarbone.
This season, Roethlisberger has completed 66.1 percent of his passes for 2,287 yards, 17 touchdowns, and four interceptions and had a 100.0 passer rating.