The Steelers have Ben Roethlisberger back. Now they might have lost Le’Veon Bell.

Bell’s knee bent badly in the second quarter of Sunday’s game against the Bengals at Heinz Field. He was helped off the field, didn’t put any weight on the leg and eventually carted into the locker room.

This is the second time in less than a year that Bell has suffered a knee injury against the Bengals. His knee was hyperextended after a tackle by Reggie Nelson in last year’s regular-season finale. On Sunday, Bell caught an eight-yard pass from Roethlisberger and was tackled by Vontaze Burfict.

In what was supposed to be a breakout season for the Steelers’ offense, Roethlisberger and Bell have played only three full quarters together.

Roethlisberger returned Sunday after missing four games with an MCL sprain and bone bruise. When he went down at St. Louis in Week 3, he was carted off the field and the situation seemed ominous for the Steelers. It looked like a season-ending injury.

But the Steelers avoided disaster, and Roethlisberger is back.

Bell’s injury also looks like it could be a season-ender, so the Steelers will have to avoid another disaster.