A league source went so far as to tell ESPN NFL Insider Adam Schefter on Sunday that the injury is a rupture, and Odom will be out for the season.
Odom was tied for the league lead with eight sacks when he got hurt during the first quarter of Houston's 28-17 victory on Sunday. Coach Marvin Lewis said afterward that the injury is "probably pretty severe," but tests would determine its extent.
The Bengals lost starting tight end Reggie Kelly to a torn Achilles tendon during training camp. Kelly had surgery and is out for the season.
Starting defensive tackle Domata Peko also suffered a knee injury in the first quarter on Sunday and didn't return, leaving the line depleted.
"We were undermanned big-time," said lineman Tank Johnson, who played with a sore foot. "But that's just the game."
Odom was been the Bengals' top defensive player during a 4-1 start. He tied the franchise record with five sacks in a victory over Green Bay in the second game of the season. On Sunday, he barged into the backfield and blocked Kris Brown's 28-yard field goal attempt on the Texans' opening drive.
One series later, he got hurt on Matt Schaub's 12-yard touchdown pass to Owen Daniels. Odom stayed on his back in pain after he got blocked while trying to get to Schaub. The medical staff looked at the back of his right leg and called for a cart to take him off the field.
Odom was the Bengals' top defensive acquisition after the 2007 season. The free agent from Tennessee signed a five-year, $29.5 million deal that included $11.5 million guaranteed. Things haven't gone well for him in Cincinnati.
He severely sprained his left foot during his first practice in training camp last year, an injury that lingered well into the season. He also suffered a shoulder injury that sidelined him for four games during the 4-11-1 season. Odom finished with only three sacks.
Quarterback Carson Palmer said the injuries on the defensive line made an impact.
"I think when you lose Antwan Odom, it hurts," Palmer said. "That's a big-time pass rusher coming off the edge. We also were without other key guys, so it made it difficult."