Awaiting update, Mets try to determine cause of deGrom's ailment

This story was excerpted from Anthony DiComo’s Mets Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

Monday should be a significant news day for the Mets, as Jacob deGrom is scheduled to undergo a follow-up MRI to see if the stress reaction in his pitching shoulder has healed well enough for him to start a throwing program. If the test comes back clean, deGrom will begin what should be roughly a month-long progression to rejoin the club.

But don’t expect him to look exactly the same as he did in March. After deGrom’s initial MRI revealed his scapular injury, coaches and team officials dug into what might have caused it. The short answer is that they don’t entirely know. The longer answer is that they might have a clue. Looking at video and motion-capture technology, the Mets determined that deGrom was jerking his arm back more violently as he brought the ball out of his glove this spring, resulting in undue stress on his shoulder while he separated his hands during his delivery. It was a subtle drift from the year before, but one centered around the joint that’s giving deGrom such trouble.

When deGrom begins throwing again, the Mets will aim to minimize the aggressive nature of his motion.

“We don’t know what actually caused the scap injury,” pitching coach Jeremy Hefner said. “What we did notice is that [the hand separation] was different.”

It’s possible, Hefner continued, that deGrom simply suffered a freak injury unrelated to his minor mechanical drift. It doesn’t take much of a step back to realize how unnatural the action of throwing a ball at high velocity can be. Pitchers break. As Mets manager Buck Showalter is fond of noting, “It’s not a normal thing to put your arm over your head and jerk it down violently 100 times every fifth day.”

“The body isn’t designed to do that,” Hefner agreed. “That’s where we just try to look at what has worked in the past. Can we get back to that? And hopefully, that keeps them healthy. A lot of this is hoping. If there was a cure for Tommy John, if there was a cure for shoulder injuries, we would obviously be doing everything in our power to do that. But no one really knows. We do know some things that tend to lead to healthy arms, but we don’t know definitively.”

What the Mets do understand is that if deGrom ramps up only to suffer another setback, it could cost him significant additional time. That would affect not only the team’s 2022 aspirations, but New York’s future prospects as well.

So if there’s even a small chance this change makes a difference, the Mets intend to pursue it.

“We just want to make sure we leave no stone unturned,” Hefner said. “We essentially have one chance -- the second half of the season or the final two-thirds of the season -- to make sure that he’s himself.”