ST. LOUIS — Instead of being in an MRI tube Saturday, as the Mets has initially planned, Jacob deGrom was in the outfield at Busch Stadium throwing from 120 feet.

Two days after playing catch and experiencing elbow soreness, which landed him on the injured list Friday, deGrom threw again and “felt completely normal,” he said. The Mets ace may not even need an MRI exam Monday, manager Mickey Callaway said, though the right-hander still plans to meet with team medical director Dr. David Altchek in New York.

“After getting some treatment [Friday] and getting things moving around, I started feeling a little better,” deGrom said Saturday. “So I decided to throw today and actually felt good with how it went.”

Placed on the injured list retroactive to April 16, deGrom is eligible to be activated Friday, when the Mets host the Brewers. The Cy Young winner is planning on making that start, he said.

Since his most recent start, last Sunday in Atlanta, deGrom had been battling a case of strep throat. He had a fever and experienced full-body soreness, he said, which took him out of his regular routine and did not allow him to throw as much as he normally likes to. If everything goes well, deGrom plans on throwing a bullpen session Monday or Tuesday.

Asked why he wouldn’t just shut it down until meeting with the medical staff on Monday, deGrom pointed to getting back on his throwing routine.

“I feel better when I throw,” he said. “We had that discussion, ‘Hey, should we just wait till we see the doctor?’ I said, ‘Well it’s not feeling bad, so why go two more, almost three more days without throwing?’ … For me, when I don’t throw, it seems that things pop up.”

Two years ago, Noah Syndergaard declined to undergo an MRI after getting scratched with shoulder and biceps discomfort. He pitched three days later and lasted just 38 pitches before missing five months with a partially torn lat.

Whether deGrom gets an MRI on Monday will be up to Altchek, the pitcher said, but he last got one March 26 before signing his five-year, $137.5 million extension and does not believe anything has changed since then.

“I had a phone call with Dr. Altchek and he doesn’t seem concerned,” deGrom said. “I’ve had Tommy John before [in 2010] and done those tests and everything feels fine with that. I’m not really worried about the spot it’s in, it’s just more being smart and not trying to go out there and do too much too early and risk a more serious injury.”

Saturday’s development marked the latest twist in the deGrom saga, which started after his second straight mediocre outing last Sunday. He was initially scheduled to make his next start Friday against the Cardinals, but that was pushed back to Saturday because of his strep throat. After deGrom said he was “just a little sore” from playing catch Thursday, Callaway announced Friday the pitcher would be scratched from his start and would fly back to New York for an MRI on Saturday.

But after getting treatment, deGrom reported so much improvement Friday that he remained with the team in St. Louis.

Plus, as Callaway said,: “It’s Easter. [Doctors] are not scheduled to work. They’re not like us. They get Easter weekend off.

“He might not get an MRI if he’s feeling this good,” Callaway added. “Probably unnecessary at this point.”

Though deGrom had not looked like himself in his past two outings — breaking a streak of 26 straight quality starts — he said it had nothing to do with a sore elbow, which he didn’t feel until Thursday.

As the Mets’ fan base universally panicked over his pending MRI, deGrom remained confident all would be well.

“I thought the whole time that I was going to be fine,” he said. “I think it was just being smart about it. It’s April right now. We got a lot of season left.”