Maciejewski was optioned to Triple-A Scranton/Wilkes-Barre following Saturday's 9-1 loss to the Rays.
Maciejewski was on the mound for the final three innings of Saturday's defeat, surrendering three hits, including a two-run homer by Randy Arozarena in the top of the seventh. After having his contract selected by the Yankees on June 30, the reliever appeared in three total contests, giving up two runs over six frames.