Garrett was one of six players suspended after a brawl with the Pittsburgh Pirates on July 30. Garrett started the benches-clearing incident by charging the Pirates dugout. He appealed the suspension.
The loss of Garrett means the Reds will be without their top reliever for an eight game stretch that also includes a four-game home series against the St. Louis Cardinals and one game at home against the San Diego Padres. He has a team-best 2.74 ERA in 52 appearances.