INDIANAPOLIS (AP) - The unbeaten Indianapolis Colts have lost starting linebacker Tyjuan Hagler for the rest of the season with a ruptured biceps.
Coach Jim Caldwell said Hagler was placed on injured reserve Wednesday.
Second-year linebacker Philip Wheeler and undrafted rookie Ramon Humber are expected to replace Hagler. Indy also will promote rookie linebacker Cody Glenn to the active roster from the practice squad.
Hagler was fourth on the Colts with 36 tackles.
Running back Donald Brown (shoulder) and cornerback Marlin Jackson (strained ACL) were expected to practice Wednesday. Caldwell did not say whether they would play this weekend.
Meanwhile, Peyton Manning is leading the AFC in passer rating and is on a record pace for yards passing. And it still isn't good enough.
The three-time MVP acknowledged Wednesday there's still room for improvement in the Colts offense. He expects more third-down conversions and more touchdowns in the red zone after settling for four field goals in last weekend's 18-14 victory over San Francisco.
The Colts (7-0) host Houston (5-3) in an AFC South clash this weekend.