MIAMI -- Injured closer Edwin Diaz will not return to the mound for the New York Mets this season.

After a six-month rehabilitation process, as Diaz worked back from a patellar tendon injury in his right knee suffered in the World Baseball Classic, the Mets have decided to turn toward the offseason and 2024 spring training for their star reliever, despite clinging to hopes most of the year that he could return down the stretch.

New York pitching coach Jeremy Hefner told MLB.com on Monday that Diaz will continue to throw bullpen sessions as the season winds down, but there will be nothing beyond that.

"It's too risky," Hefner said. "I'm not as concerned about the pitching. It's more about fielding and a ball getting hit back at him and he has to get out of the way, and really it's about covering first base and covering a bunt. I have very little concern about him pitching at the moment.

"If we were in a different situation as a team, we definitely could have pushed to the point where he'd probably be pitching in games right now. Obviously you saw with our team this year, he's an integral part. We can't do anything to risk next year by reinjuring an already unprecedented injury. That's where we're at right now."

Diaz underwent surgery on March 16 after suffering the injury at loanDepot Park in Miami. He was celebrating after recording the final out of Puerto Rico's win over the Dominican Republic at the time. Had he not been in the WBC, he would have been pitching for the Mets in spring training games.

Mets manager Buck Showalter, speaking before a 2-1 win over the Miami Marlins, declined to speak about Diaz's timeline but said that "you've got to be careful about doing something just because of curiosity."

On Aug. 28, a return seemed promising after Diaz threw his first outdoor bullpen at New York's Citi Field. The 29-year-old right-hander spoke to reporters the next day, saying, "my goal was to be ready in six months. And I'm working on that."

Diaz, at the time, said he was clocked in the low-to-mid 90s in that session and that "I feel healthy right now, and I'm pitching again."

Diaz had 64 saves and a 4.00 ERA for the Mets from 2019 to 2021, then registered 32 saves with a 1.31 ERA and 118 strikeouts in 62 innings last season. He agreed in November to a five-year, $102 million contract, a record deal for a closer.

The Associated Press contributed to this report.