The unbeaten Colts will be without starting linebacker Tyjuan Hagler for the rest of the season due to 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 against Houston this weekend.