Chiefs LB Derrick Johnson suffers ruptured left Achilles vs. Raiders

KANSAS CITY, Mo. -- Kansas City Chiefs linebacker Derrick Johnsonsuffered a ruptured left Achilles tendon in the second quarter of Thursday night's 21-13 win over the Oakland Raiders, coach Andy Reid confirmed.

Johnson, a four-time Pro Bowler, threw his helmet in frustration after the injury. He had to be helped off the field without putting any weight on his foot, and the Chiefs immediately ruled him out for the game.

"A sad deal there,'' Reid said. "I felt a little bit of a letdown when it happened."

Johnson, who missed most of the 2014 season because of a torn right Achilles, was injured on what turned out to be the Raiders' only touchdown drive of the game.

"Justin [Houston] and [Eric Berry] kind of got everybody going and reeled everybody in," Reid said. "The thing they were saying is, that's the last thing that D.J. would want, is a letdown. He's such a big part of our team."

Johnson, who along with punter Dustin Colquitt is the longest-tenured Chiefs player, arrived in Kansas City as its first-round draft pick in 2005. He remains one of the Chiefs' top defensive players, as he rarely comes off the field in running or passing situations.

His backup is D.J. Alexander, a fifth-round draft pick last year.

The Chiefs led 21-3 when Johnson went down Thursday, and his injury seemed to briefly deflate the Kansas City defense. Oakland proceeded to march 92 yards for its lone touchdown just before halftime.

But the Chiefs bounced back in the second half, limiting the Raiders to a field goal to preserve the win.

"He's a guy I respect so much, and just to see the look on his face when it happened, it looked serious,'' Chiefs quarterback Alex Smith said. "There's not a guy in the locker room that doesn't look up to D.J., so yeah, in a big game like that, hat's off to our defense for responding.

"Something like that can hurt you big time, and our guys didn't miss a beat."

The Associated Press contributed to this report.