Pittsburgh Steelers running back Le'Veon Bell reportedly has a significantly torn MCL, as well as other damage to his knee, and is expected to miss the rest of the season, according to NFL reporter Ian Rapoport.

Bell had to be carted off the field Sunday against the Cincinnati Bengals when his knee bent backwards after being tackled near the sideline. Bell was catching a pass from Ben Roethlisberger, who returned to action Sunday after suffering an MCL injury of his own in week three against the St. Louis Rams.

Bell's injury looks to be much more significant, and Steelers players are upset by the celebration Bengals linebacker Vontaze Burfict engaged in after the tackle. "He's that type of guy," said Steelers guard Ramon Foster, via ESPN. "That type of guy will get his sooner or later. If you've played against him, you know what I mean by it. He'll play it off, act dumb about it, but you don't run across the field acting hyped, celebrating, jumping up and down when a guy goes down like that."

After the game Burfict said he didn't know Bell was injured, and said that the two were friends. Initial reports said the Steelers were optimistic about Bell's injury because of the status of the ACL, but there was significant enough damage to tear his MCL badly and he is likely now set to miss the rest of the 2015 season.

The Steelers will look to running back DeAngelo Williams to carry the load for them this season, but the team has an uphill battle after falling to 4-4 on the season Sunday. Bell is arguably one of the best running backs in the league, and it will be difficult to replace a player of his caliber.