The pelvis is in “full-blown” condition after a partial tear was surgically repaired, the team said Wednesday.
The injury happened during the Ravens-Bengals game in Cincinnati in the third quarter on Aug. 15.
The team did not disclose the extent of the damage to the pelvis or the severity of the surgery.
The Ravens were down 14-3 at the time.
A Ravens spokesman said it is too early to comment on the situation.
The Steelers are currently 2-0 in the playoffs after beating the Baltimore Ravens in the divisional round of the playoffs last year.
The Chargers were the only other team to beat the Ravens in last year’s playoffs.
The Ravens have won four of the last five meetings with the Steelers, but they lost to them in overtime last year in a 38-32 overtime victory.