The Braves sent left-handed pitcher Chris Jones to the Orioles in Wednesday's deal. The 24-year-old was pitching at Double-A Mississippi.
The 35-year-old Ayala is expected to join the Braves when they open a series Friday in Washington. He is 1-0 with a 9.00 ERA in two appearances this season, after going 5-5 with a 2.64 ERA and one save in 66 games for the Orioles in 2012.
The Braves were seeking more depth in their bullpen because of an injury to Jonny Venters. He was shut down for a month after receiving an injection in his sprained left shoulder.