Chiefs' Derrick Johnson on season-ending surgery: "I will play again"

Johnson injury a tough blow for Chiefs (0:44)

Darren Woodson breaks down how Derrick Johnson's Achilles injury will affect the Chiefs. (0:44)

KANSAS CITY, Mo. -- Kansas City Chiefs linebacker Derrick Johnson said he will have surgery to repair his torn left Achilles tendon with the expectation that he will return to play for Kansas City next season and perhaps beyond.

Johnson suffered the injury in the second quarter of Thursday night's 21-13 win over the Oakland Raiders.

A 12-year veteran, Johnson has two seasons remaining on his contract.

"Yes, I will play again," he said.

‎Once the surgery is completed, Johnson said he intends to commit himself to helping the team's young linebackers prepare for the team's remaining games.

"My job now is to help us get a ring anyway possible," he said.

Johnson said he has interest in becoming a coach when his playing career ends so he views this as an internship of sorts.

Johnson missed most of the 2014 season because of a torn right Achilles.

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.

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 after the game. "I felt a little bit of a letdown when it happened.

"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 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 Thursday. "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.