Both were placed on injured reserve Monday. Powers injured the big toe on his right foot. Nevis hurt his hand in Thursday's victory at Jacksonville.
The moves allowed Indy (6-3) to activate rookie nose tackle Josh Chapman, a fifth-round pick out of Alabama. Chapman has been on the reserve-non-football injury list since the start of training camp after playing most of his final college season with a torn ACL in his left knee.
Indy also promoted rookie tight end Kyle Miller from the practice squad to the active roster.
Powers is likely to be replaced in the lineup by Darius Butler, who had two interceptions and recovered a fumble last week.