Marinaccio was optioned to Triple-A Scranton/Wilkes/Barre on Thursday.
Marinnacio made eight appearances in the majors since being recalled April 13 and posted a 1.42 ERA and 0.79 WHIP with an 10:5 K:BB across 12.2 innings. Despite being effective, he'll head back to the minors to make room for Nick Burdi (hip).