CINCINNATI — Kodai Senga wants to be a helpful part of a playoff team in late September and throughout October, which led to his decision — and it was his decision — to leave the big-league Mets in early September. 

The struggling but talented righty accepted a demotion to Triple-A Syracuse on Friday so he can try to cure what has ailed him during a brutal stretch. He will need to spend at least 15 days at the lower level and will be eligible — but not guaranteed — to return with about a week left in the season. 

By that point, the Mets and Senga are hoping he will be a different pitcher — more like the All-Star he was in 2023 or the pitcher who sure looked like an All-Star throughout this season’s first half. 

Kodai Senga has struggled lately. Charles Wenzelberg / New York Post

“He wants to do what’s right for the team,” president of baseball operations David Stearns said before beginning a series at Great American Ball Park. “And he believes that he can be a part of a playoff run here. He very much wants to be a part of a playoff run here. 

“And I think we all got to the point that the best possible chance for him to do that is take a step back, be able to work on what he needs to work on in a controlled environment and go from there.” 

Kodai Senga walks off the mound during a start against the Braves on Aug. 14, 2025. Charles Wenzelberg/New York Post

Moving Senga to the bullpen “didn’t feel like the right thing to do,” Stearns said, with a pitcher so focused upon his routine. His recent results — a 6.56 ERA in his past eight games for a team trying to make a division charge and trying to hold off wild-card competition — reflected that he could not continue trying to figure out his struggles on the fly. So the Mets presented the notion of using a minor league option to Senga earlier this week, and he was “very open from the beginning,” manager Carlos Mendoza said. 

Senga talked with his camp and accepted the Mets’ plan despite a contractual ability to reject a stint in the minors. If there were concerns from his own agency or the MLBPA about the precedent of consenting to a minor league option, they did not matter in the end. 

“So much respect for the player,” Mendoza said of Senga, who will be replaced in a six-man rotation by Brandon Sproat. “[He was] obviously disappointed — he wants to be here; he wants to help us — but he understands where he’s at physically and where we’re at as a team and where he’s at performance-wise.” 

Senga will not immediately jump into games with Syracuse. A pitcher so preoccupied with his mechanics will throw in several bullpen sessions before likely receiving a start next weekend. Mendoza said Senga will make a “couple starts” before the club and player huddle to decide upon a next step. 

The fall is significant for the Japanese star signed to a five-year, $75 million pact in December 2022 who was brilliant in his rookie season, in which he received Cy Young votes, and brilliant in this season’s first half after missing most of last year due to injury. 

Kodai Senga pitches during the Mets-Marlins game on Aug. 31, 2025. Robert Sabo for NY Post

In his first 13 starts this season, Senga owned a 1.47 ERA. He then strained his hamstring while covering first base, returned in July and has looked like a completely different pitcher. There have been innings when he has been dominant, and there have been innings when he has been crushed. There have been more of the latter. 

“A lot of times, these lower-half, lower-body injuries can cause us to compensate in other ways,” Stearns said of Senga, who continues to state he is healthy. “Maybe that’s one of the things that’s going on here that’s sapped him of velocity a little bit, made him a little less consistent than he’s used to.” 

Senga has placed blame just about everywhere, from his mechanics to his pitch selection to the quality of his stuff. 

He wants to know what precisely is wrong and is willing to fix it at a level to which he did not have to stoop. 

“He wants to figure this out,” Stearns said. “I think getting him a little bit of time away from elite competition, away from the pressure of a playoff race, was the right thing to do.”