TitansOnline.com reports that Nick Harper has a broken right arm:

Tennessee cornerback Nick Harper hurt his right arm early in the third quarter and was knocked out of the game against Indianapolis. Harper was hurt on the Colts’ opening drive after a turnover in the second half and he walked immediately to the locker room from the field, accompanied by a doctor while Harper held his arm at the wrist and wriggled his fingers. That left the Titans without both their starting cornerbacks with rookies in their place.