Howard was recalled from Triple-A Lehigh Valley on Wednesday.
Howard had been stretching out as a starter in the minors since the end of June, but he'll be available to provide length out of the bullpen in Wednesday's series finale against the Yankees. The right-hander threw three innings during his most recent appearance Saturday, so he should be able to provide multiple innings if needed. Outfielder Mickey Moniak was optioned to Triple-A Lehigh Valley in a corresponding move.