The Bengals’ best defensive player is done for the season.

Geno Atkins, the star defensive tackle who signed a five-year, $55 million contract less than two months ago, suffered a torn ACL on Thursday night in Miami. The Bengals’ medical staff believed on initial diagnosis that Atkins had suffered the serious injury, and Bengals head coach Marvin Lewis confirmed today that Atkins is done for the year.

That’s an enormous blow for the Bengals. Atkins is one of the most disruptive players in the middle of the line in the entire league, and he’s extremely important to the Bengals both as a pass rusher and a run stuffer. There’s really no way to replace a player like Atkins.

At 6-3 in a weak division, the Bengals remain the favorites to win the AFC North. But losing Atkins is a major blow to any hopes the Bengals had of a run to the Super Bowl.