Jacob deGrom’s next start uncertain with forearm tightness

PITTSBURGH — The only thing stopping Jacob deGrom from being the best pitcher on the planet is his own health.

The Mets ace is dealing with his fifth injury this season — this time it’s right forearm tightness — and he has been shut down from throwing until that tightness completely disappears. His next scheduled start is unknown.

The team believes his current injury is not connected to the right flexor tendinitis deGrom experienced last month. In fact, the Mets believe all of his myriad of minor injuries this season are not connected.

DeGrom received an MRI on Friday, which revealed no structural damage, after he could not complete his usual side session at PNC Park. The right-hander threw about 10 pitches before his session was shut down due to the tightness. The Mets did not make DeGrom available to speak to reporters on Saturday, but he told his manager that he initially thought the tightness was a routine discomfort in between starts that would go away. Luis Rojas claimed he learned of deGrom’s injury on Saturday morning.

“He told me that he felt it in a side [session] he threw before the [All-Star] break,” said Mets manager Rojas. “He played catch at home and intended to throw a side there too, and he felt the tightness again and he just stopped throwing.”

The Mets continue to be perplexed by the cause of deGrom’s injuries this season. The 33-year-old has dealt with back stiffness, right lat and side tightness, right flexor tendinitis, right shoulder soreness and now, right forearm tightness. Rojas, as has been the case all season, again repeated on Saturday that the team believes his injuries, which have all occurred on the right side of his body, are not related.

These string of ailments have not impacted deGrom’s performance on the mound. When he is healthy and pitching, he continues to be dominant. The ace has the best ERA (1.08) in MLB, the most strikeouts (146) in the National League, and a 7-2 record across 15 starts and 92 innings pitched this year. His WHIP (0.554), FIP (1.24), strikeouts per nine innings (14.3) and ERA+ (365) are all lowest in the majors.

The Mets obviously cannot replace deGrom in the rotation, but they do have a frontline right-hander ramping up in the minor leagues right now.

Carlos Carrasco has made one rehab start so far as he continues his long recovery from a torn right hamstring. Though the Mets’ initial timeline on Carrasco’s return, which is penciled in for the end of this month, has not changed, the team does not believe it is prudent to speed up his rehab process due to deGrom’s latest injury. The Mets do not have a starter announced for Monday’s series opener at Cincinnati.

“Right now, I don’t think we can rush any player’s rehab stint or progression just because this has happened,” Rojas said. “I don’t think we just speed up some things. That’s something to wait on how Cookie is. ... But wanting him to come because we have a need, that’s probably not ideal.”

DeGrom’s forearm tightness has already caused him to miss his turn through the rotation in the second half of the regular season. Given the number of injuries he’s sustained this year, the Mets will likely play it safe with their ace and depend on his honesty and evaluation of his own body to determine when it’s best for him to return to the mound. For now, the Mets’ three-game lead in first place gives them the space to adopt a leisurely recovery timeline with their ace. But, in a troubling trend, if history has shown the Mets and deGrom anything this season, there’s no telling when his next injury may occur.