KANSAS CITY, Mo. -- Chiefs inside linebacker Derrick Johnson, the team's leading tackler, ruptured his left Achilles tendon late in the first half of Kansas City's Thursday night game against the Oakland Raiders at Arrowhead Stadium.
Johnson, a 34-year-old who was the Chiefs' first-round choice in the 2005 draft, is done for the season.
Johnson was chasing a play to his right, when his left foot gave out and he tumbled to the ground. He immediately sat up, took his helmet off and tossed it to the ground.
Medical personnel worked immediately on his Achilles before he was assisted to the sideline.
Johnson missed all but the first game of the 2014 season with a torn right Achilles.
"It's a sad deal," Chiefs coach Andy Reid said of losing Johnson. "We had a letdown after it happened. But Justin (Houston) and Eric (Berry) got them going again. That would have been the last thing D.J. wanted, would be a letdown."
The Chiefs beat the Raiders 21-13.