The Athletics recalled Kelly from Triple-A Las Vegas on Saturday.
With Luis Severino (shoulder) headed for the injured list, Kelly will return to the majors to provide the big club with some additional bullpen depth. Since being demoted to Triple-A in early April, the 33-year-old righty has posted a 4.91 ERA and 1.62 WHIP over 14.2 innings. He'll likely be limited to low-leverage work as long as he's with the A's.