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.