Manager Mickey Callaway said deGrom now may not need to have the MRI, but will be checked out by the team's medical staff when the Mets return to New York on Monday.
On Friday, the Mets said the reigning Cy Young Award winner would be placed on the 10-day injured list, retroactive to Tuesday. DeGrom was scratched from his Saturday start against the Cardinals.
"It's just a little sore," deGrom said in St. Louis after throwing in the outfield.
"I had been sick since Atlanta and kinda had a whole-body soreness. For me when I don't throw, it seems that things pop up and I wasn't on a normal routine. I was trying to just get enough in to be able to make my start and I felt a little soreness in my elbow. I decided to say something and talked it over with Mickey and [pitching coach] Dave [Eiland].
"We decided it's early in the season, I've been sick, what's the point in trying to push it and then after getting some treatment yesterday and getting things moving around it started to feel a little better, so decided to throw today and it actually felt good."
DeGrom had Tommy John surgery in 2010.
He was dominant while pitching 13 scoreless innings and striking out 24 in his first two outings, extending his streak to a record-tying 26 straight quality starts. But he lost his past two starts while allowing a total of nine runs on 13 hits -- including five homers -- and five walks in nine innings.
DeGrom posted a 1.70 ERA in 32 starts last season. He signed a $137.5 million, five-year contract in March, just before Opening Day.
Mets general manager Brodie Van Wagenen said Friday that deGrom could return April 26 when the Mets start a series at home against Milwaukee.