Lopez was recalled from Triple-A Syracuse before the game and had to immediately sit out.
Mets manager Buck Showalter said the suspension had been reduced. Lopez had appealed after Major League Baseball ruled that he intentionally threw at Phillies slugger Kyle Schwarber on May 1, an inning after Mets star Francisco Lindor was hit by a pitch.
Showalter was suspended one game for the incident.
Lopez was sent to the minors after the game. The 29-year-old righty has pitched twice in relief for the Mets this year, allowing three runs in two innings.