Early in the 1999 season, McNair was diagnosed with an inflamed disk following Tennessee's 36–35 win over the Cincinnati Bengals, and needed surgery. He was replaced by veteran Neil O'Donnell. Over the next five games, O'Donnell led the Titans to a 4–1 record. McNair returned against the St. Louis Rams, and with McNair starting, Tennessee won seven of its last nine games to finish 13-3.