"As long as it doesn't flare up in the next 24 hours, he should be fine," Eiland said.
With scheduled off-days both Monday and Thursday this week, the Mets can pitch Jacob deGrom and Steven Matz on five days' rest Friday and Saturday in the Subway Series. That sets up Syndergaard for the Sunday night start.
Outfielder Yoenis Cespedes took three of the five at-bats against Syndergaard, which could also be significant for the Mets. Cespedes has been on the disabled list since May 16 with what the Mets termed a mild strain of his right hip flexor.
Cespedes declined comment after the simulated game, but Mets manager Mickey Callaway said the team hopes to have Cespedes run the bases and do some work in the outfield before Wednesday's game against the Orioles.
"And then we'll go from there," Callaway said, without detailing how soon Cespedes could return to the lineup.
The Mets did get two players back from the disabled list Tuesday, with third baseman Todd Frazier returning after missing 24 games with a left hamstring strain and reliever Anthony Swarzak coming back after missing two months with a strained left oblique.
"I'm fired up and ready to go," said Frazier, who was on the DL for the first time in his eight-year Major League career. "I guess I needed that time off. I've played through pain. This was one of those areas where you really can't do that."
Swarzak, expected to be a key part of the Mets' bullpen when he signed as a free agent last winter, pitched just twice before going on the DL. He said the lengthy absence was all due to an original injury he sustained in Spring Training, which took longer to heal than he had expected.
To make room on the roster for Frazier and Swarzak, the Mets optioned pitcher Gerson Bautista to Triple-A Las Vegas and designated left-hander Buddy Baumann for assignment.
Danny Knobler is a contributor to MLB.com based in New York.