The move, announced Tuesday, is retroactive to July 25.
Banuelos was acquired by the Braves in a trade with the Yankees last January. He made his big league debut on July 2 and was 1-2 with a 2.49 ERA in five games, four of them starts.
He was scheduled to start Wednesday against the Baltimore Orioles. His replacement has not been named.
Braves manager Fredi Gonzalez said of the injury: ''We don't think it's anything really serious.''
Banuelos had Tommy John surgery in 2012 and missed the entire 2013 season.
Atlanta filled out the pitching staff by purchasing the contract of right-hander reliever David Carpenter from Triple-A Gwinnett, where he had a 0.71 ERA.