INDIANAPOLIS - The unbeaten 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 team with 36 tackles.
Running back Donald Brown (shoulder) practiced Wednesday, while cornerback Marlin Jackson (strained ACL) did not. Also missing practice were receiver Anthony Gonzalez (knee), cornerback Kelvin Hayden (knee) and safety Bob Sanders (elbow). Defensive end Dwight Freeney was held out to rest.