The Athletics traded Spence to the Royals on Thursday in exchange for A.J. Causey.
After being DFA'd by the A's on Tuesday, Spence will recapture a 40-man roster spot by moving to Kansas City. The 27-year-old reliever turned in a 5.10 ERA and 1.44 WHIP across 84.2 innings last season and will be in the running for a spot in the Royals' Opening Day bullpen. He has two minor-league options remaining, however, so there is a chance he opens the year at Triple-A Omaha instead. Alec Marsh (shoulder) was placed on the 60-day IL in a corresponding move.