"We had an MRI taken on him and ran it through two doctors just to have a second opinion, as well, and both doctors had the same prognosis from the imaging: It just shows as a normal shoulder a pitcher would have and there's no concern," Rojas said, adding that deGrom played catch Thursday.
Rojas said that the team plans to take "a day-by-day approach" with deGrom and that there are no plans right now to place him on the injured list. The Mets also aren't sure when he'll make his next start.
"I don't see how it would change today, doing an IL stint," Rojas said. "It's going to be a normal shoulder in 10 days. I'm less concerned [because] he's playing catch today."
DeGrom left Wednesday night's start against the Chicago Cubs with shoulder soreness. It marked the third time he has left a start with an injury this season, including Friday against the San Diego Padres with elbow soreness and May 9 against the Arizona Diamondbacks after five innings with right side tightness.
Rojas said Thursday that none of deGrom's injuries are connected.
"This is an isolated thing from the right forearm or the flexor tendinitis," Rojas reiterated. "It's something that happened yesterday. We checked him after the game and checked him today, and everything is normal."
DeGrom, 32, struck out eight of the nine batters he faced over three innings, and he drove in a run with an RBI single in the second inning. The Mets aren't ruling anything out in terms of what caused his latest ailment, including even the possibility of it happening on a swing at the plate or simply because of how hard he throws. DeGrom has the highest average fastball velocity (99.2 mph) of anyone in baseball.
"We want to pay attention to this thing, on a day-by-day approach," Rojas said.
DeGrom's three shutout innings Wednesday lowered his ERA to 0.54 -- he has given up only four earned runs all year -- while his RBI gave him six on the season. He has 111 strikeouts in 67 innings.