Ed Bouchette of the Pittsburgh Post-Gazette reported the diagnosis after Pittsburgh's 20-17 win. Mike Florio of Pro Football Talk later reported Haden has a "slight" fracture in his leg and won't need surgery. He is expected to miss three weeks, per Florio, though ESPN.com's Jeremy Fowler reported Haden could be out up to six weeks.
Haden was injured after appearing to make contact with a Colts player running down the sidelines.
The Steelers signed Haden in August after he was released by the Cleveland Browns. The 28-year-old has started each of Pittsburgh's first nine games this season, and his five pass breakups are tied for third on the defense.
Coty Sensabaugh took over for Haden in the Steelers secondary.