ST. LOUIS _ Jacob deGrom flew back to New York on Friday and is scheduled for an MRI on Saturday after his right elbow was "barking" while playing catch Thursday, Mickey Callaway said.
Callaway said the Mets are being cautious with their ace, the 2018 NL Cy Young Award winner, hence the tests. DeGrom already had Tommy John surgery to replace his torn ulnar collateral ligament in 2010.
"We're not sure exactly what it is, so we want to get it checked out," Callaway said. "He's just a little tender in the elbow. We don't know if it's just from general fatigue. So we're being overly cautious at this point. We have 90 percent of the season left and feel no reason to push him too much at this point. There's just no reason to do it.
"He hasn't really felt it until (Thursday)."
The Mets haven't announced who will start in deGrom's place Saturday against the Cardinals. Noah Syndergaard is scheduled to pitch in St. Louis on Sunday, with Steven Matz set for Monday at Citi Field against the Phillies.