Atlanta selected Stephens' contract from Triple-A Gwinnett on Monday.
Stephens will provide the big club with a fresh relief arm heading into Monday's doubleheader against the Phillies. This will be the first stint in the big leagues this season for the 29-year-old reliever, as Stephens has posted a 3.28 ERA and 26:4 K:BB over 24.2 frames with Gwinnett.