CINCINNATI -- Antwan Odom had surgery for a torn Achilles' tendon Monday, ending his season and leaving the Bengals with a big hole on their defensive line.
Odom was the Bengals' top pass rusher, tied for the NFL lead with eight sacks, but he hurt his right Achilles' tendon during a 28-17 loss to the Houston Texans on Sunday. The Bengals put Odom on injured reserve, but they didn't immediately fill his spot.
Odom wasn't the only Bengals defensive lineman hurt against the Texans. Domata Peko suffered a knee injury on the opening series and didn't return. Coach Marvin Lewis declined to provide any information on that injury Monday, other than to say that "it's not believed to be real severe."
Frostee Rucker was inactive Sunday with a sprained ankle. Tank Johnson, hobbled by a sore foot, returned after missing two games.
With so many starters hurt, the defensive line is an injury-depleted mess.
"Just the fact that I've got two good legs is a blessing," said Johnson, who has plantar fasciitis in his right foot. "It's tough. Guys are banged up. It is what it is, and we're going to play through it."
The defensive line is the second area wiped out by injuries this season. The Bengals lost their top two tight ends for the season when Reggie Kelly tore an Achilles' tendon and Ben Utecht suffered a major concussion during training camp. Their backups have struggled, repeatedly dropping passes.
Now the defensive line -- a key to Cincinnati's 4-2 start -- is missing its best player and will have to turn to backups to pull it through. The Bengals host the Chicago Bears (3-2) on Sunday.
"Antwan has done some things this year that no one's done," Johnson said Monday. "He's a great player and a great asset to our defense. Antwan has a lot of natural ability. He can reach over five people and grab you with his long arms."
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Rookie defensive end Michael Johnson, a third-round draft pick who has played on passing downs, likely will have an expanded role.
"Every week, he gets quite a few snaps," Lewis said. "I think Michael played his best football that he played this season yesterday. Hopefully that continues as a trend. He'll have an opportunity to do more and more."
The defense had by far its worst game of the season Sunday, one week after it played its best. The Bengals dedicated their 17-14 win at Baltimore to the family of defensive coordinator Mike Zimmer, whose wife, Vikki, died a few days earlier. The inspired defense allowed only one touchdown.
Against the Texans, the Bengals were sloppy. Matt Schaub repeatedly completed passes to wide-open tight ends and running backs, and he threw receiver screens that went for long gains. Houston rolled up 26 first downs and 472 yards, the third-highest total in franchise history.
Tank Johnson dismissed suggestions that the defense had a letdown after the emotional game in Baltimore.
"Everybody's talking about this emotional stuff? Why is everybody so emotional?" Johnson said. "We're fine. We're grown men. You deal with stuff and you move on."
The Bengals had won four in a row, the last three against AFC North rivals. By beating Pittsburgh, Cleveland in overtime and Baltimore, they moved into sole possession of first place for one week. The loss on Sunday left them tied with Pittsburgh.
Quarterback Carson Palmer also shrugged off suggestions the Bengals were flat after those three emotional division wins.
"That's just making an excuse," Palmer said. "We played three emotional games -- one game went five whole quarters -- but if we start pointing fingers and using excuses like that, that doesn't make us better. That's a negative mindset."
On a positive note, offensive tackle Andre Smith is expected to rejoin the Bengals in practice this week, and could be on the field for a game Nov. 8 against Baltimore.
Smith, the sixth overall pick in April, missed all of training camp in a contract impasse. Two days after he signed, he broke a bone in his left foot during a non-contact drill.
Copyright 2009 by The Associated Press
