Encarnacion, who had hit his 34th home run in the third inning of a 10-4 victory against the Tigers in Game 1, exited with a strained left oblique in the seventh inning. The 36-year-old designated hitter missed nearly a month of action with a fractured right wrist earlier this season.
“He felt it, I guess, in his first at-bat and, obviously, homered in his second at-bat,” Yankees manager Aaron Boone said. “My understanding is [that] he was fine swinging; he was just getting it a little when he was coughing or whatever.
“Again, we hope it’s minor and we got ahead of it, but we won’t know until we get him checked out, obviously. Edwin even took his third at-bat and said he wasn’t feeling anything swinging. Hopefully we’re ahead of it, but we’ll see.”
The injuries continued in Game 2 of the doubleheader, when catcher Gary Sanchez exited with left groin tightness, the Yankees said. Sanchez drew a walk in his lone at-bat and was caught stealing in the third inning. He was replaced by Kyle Higashioka in the bottom of the fourth.
Sanchez missed 16 games earlier this season with a strained left groin.
For the Yankees — who have set a major league record by sending 30 players to the injured list this season — losing Encarnacion would be another blow heading down the stretch after likely having lost outfielders Mike Tauchman and Aaron Hicks for the season.
Nonetheless, Boone remained optimistic that Encarnacion’s injury is not severe, particularly because it wasn’t affecting his power swing.
“His presence in our lineup is huge, so I don’t want to start speculating when we don’t know what it is and hope that it’s minor,” Boone said. “I think it goes without saying how big of a presence he is in the middle of our order.”
In seven games since coming off the IL on Sept. 3, Encarnacion was hitting .281 with three home runs and eight RBIs. He suffered a fractured wrist after being hit by a pitch from Boston Red Sox reliever Josh A. Smith on Aug. 3.
Happ, meanwhile, started the first game Thursday, taking a shutout into the fifth inning before giving up a two-run homer and a single. He was then removed by Boone.
Boone said after the game that Happ had been bothered by left biceps tendinitis near his shoulder for a few starts and it had been “planned ahead of time” to send him back to New York after Thursday’s start.
“It’s nothing that we’re too concerned about,” Boone said. “… We don’t think it’s significant. Obviously, he’s been throwing the ball really well, but it was just somewhere where we wanted to get him back there [for Dr. Christopher Ahmad] to see him.”
Happ, who did not factor into Thursday’s decision and is 12-8 with a 5.07 ERA and 130 strikeouts this season, said the discomfort has “been getting progressively to the point where we’ll get it looked at.”
“Hopefully we can figure something out, just to get some relief in between to make sure we’re getting the work in [that] we need to,” Happ said.
He said he wanted to pitch Thursday and that he “voiced my opinion” about it with Boone.
“Of course I wanted to,” Happ said. “Generally the organization, most organizations, take a cautious approach. I think after we all talked and I expressed exactly how I am feeling and the fact we’ve been through this before … I definitely wanted to pitch.”
Earlier Thursday, Boone said he expects pitcher Luis Severino to return to the starting rotation next week. Severino has yet to pitch this season while recovering from right rotator cuff inflammation and a lat strain.
The Associated Press contributed to this report.