Atlanta recalled Petersen from Triple-A Gwinnett on Sunday.
He'll take over the 26-man active roster spot that previously belonged to starter AJ Smith-Shawver, who was optioned to Gwinnett ahead of the activation of Spencer Strider (elbow) from the injured list next week. The hard-throwing Petersen is likely to occupy a low-leverage role out of the Atlanta bullpen after submitting a 5.95 ERA and 1.63 WHIP over 19.2 innings in the majors last year between stops with the Dodgers and Marlins.