Cincinnati Bengals defensive tackle Geno Atkins was helped off the field with a knee injury during the first half of Thursday night's loss to the Miami Dolphins, and Bengals coach Marvin Lewis said after the game that the team believes Atkins as an "ACL situation.
NFL Network also reported the team fears Atkins suffered a torn ACL, which would end his season.
The two-time Pro Bowl selection was helped off the field by teammates and did not return to the game. The Bengals announced at halftime that Atkins was out for the remainder of the game.
Atkins was hurt on a 3-yard run by Miami's Lamar Miller in the second quarter. A pile of players fell on Atkins after he lost his footing while being blocked.
In the first quarter, Atkins sacked Dolphins quarterback Ryan Tannehill, giving him six for the season.
A first-team All-Pro selection last season, Atkins signed a five-year, $55 million contract extension in September. The 25-year-old made the Pro Bowl the past two seasons and last year finished with 12 1/2 sacks.
The injury left the Bengals short-handed at Atkins' spot. Brandon Thompson, the team's third-round pick in the 2012 NFL Draft, took his place. Reserve defensive tackle Devon Still was inactive for the game.