For the fourth time in five games, the Atlanta Falcons have switched starting quarterbacks with coach Bobby Petrino turning the job back over to Joey Harrington for the Thanksgiving night matchup against the Indianapolis Colts. Harrington, 29, has started eight games for the Falcons this season and has posted a record of 3-5, including two straight victories before being replaced by Byron Leftwich last week. Petrino had committed to Lefwich for the rest of the season when he elevated him to the top of the depth chart for the Oct. 21 game against New Orleans. But Leftwich suffered an ankle injury in that game, underwent surgery, and missed two games before returning last Sunday against the Tampa Bay Bucs. Leftwich struggled against the Bucs, turned the ball over three times, and was replaced by Harrington who led Atlanta to its only score in a 31-7 defeat. The former Jacksonville starter also suffered a tailbone injury against Tampa Bay. It is not known yet if he will be available for the Thanksgiving game.