The Padres designated Marinaccio for assignment Sunday.
The 30-year-old will lose his spot on the 40-man roster after submitting a 4.79 ERA, 1.45 WHIP and 38:18 K:BB across 47 innings in 33 relief appearances for San Diego. He'll give up his spot on the active roster to right-hander Randy Vasquez (ankle), who was reinstated from the 15-day injured list.