Stanton, who had been sidelined by left Achilles tendinitis since July 23, returned to the lineup as designated hitter for the start of a four-game series against the Oakland Athletics on Thursday night.
Batting third, he connected on a two-out, bases-loaded single to drive in two runs in the second inning, before collecting his third RBI with a bases-loaded walk in the third inning of his side's 13-4 win.
Cortes' loss is a big one for the first-placed Yankees, who entered Thursday with a seven-and-a-half game lead over the Tampa Bay Rays in the American League East.
The left-hander is 9-4 with a 2.68 ERA in 23 starts, while throwing a career-high 131 innings this season. An All-Star for the first time earlier this year, Cortes said he felt discomfort in his push-off leg early during his last start against the Toronto Blue Jays on Sunday and pitched through it. He expects to return on schedule and contribute to the September stretch run.
''I feel like if there was a time for it to happen, it would be now, instead of the middle of September or late September going into the playoffs or October,'' Cortes said. ''I've got to take care of my body so I can be one of the guys when playoff time comes around.''
Cortes played light catch from between 100 and 120 feet at the Oakland Coliseum on Thursday, making 30-40 throws. He could throw in the bullpen in the next few days.
''I'm hoping 15 days is enough,'' he said. ''I think the fact that I'm feeling pretty well – I don't think there will be any hiccups along the way.''
The Yankees could move Clarke Schmidt into the rotation after he was stretched out to pitch starter innings when he was sent to the minors on August 1.
Luis Severino is recovering from a lat strain, but is expected to return to the rotation from the injured list by mid-September.