Kodai Senga’s long-awaited Mets season debut comes with ace expectations

ST. LOUIS — Kodai Senga’s spring training performances, taken as a whole, reverberated maybe the loudest of any by a pitcher the Mets had in camp.

The right-hander’s velocity reached new heights, and his secondary pitches were sharp. Optimism now flows that the Mets will unveil an ace at the back end of their new rotation.

On Tuesday he will return to a major league mound in a game that matters for the first time since Aug. 31, after which his second-half struggles prompted the Mets to ask Senga if he would agree to a minor league assignment. Senga accepted the demotion and pitched the final month for Triple-A Syracuse.

This spring he pitched to a 1.86 ERA in his three Grapefruit League appearances with 11 strikeouts in 9 ²/₃ innings. His only runs allowed were on two solo homers in his first start.

“The results are the results and I take them with a grain of salt,” Senga said through his interpreter before departing camp. “But if you look at the metrics of the pitches that I am throwing, I think that does translate into the season. Some are good and some are not as good, but compared to the previous years I feel I am performing at a higher level, so I have just got to keep it up in the season.”

Senga’s fastball touched 99 mph during spring training and Mets officials were encouraged by the manner in which he carried himself. Last season Senga averaged 94.7 mph with his four-seam fastball.

Mets Pitcher Kodai Senga throws live batting practice during Spring Training at Clover Field, Thursday, Feb. 19, 2026, in Port St. Lucie, FL. Corey Sipkin for NY Post

“The way he came, the treat early on — how built-up he was and how physical he was and how his body felt was really exciting,” pitching coach Justin Willard said. “And then to kind of carry that into spring training and continue to put up big velocities, really good shapes and pound the strike zone was really good to see.”

Senga was rolling in mid-June, pitching to a 1.47 ERA when he hit the injured list with a strained right hamstring on a coverage play at first base. Senga missed a month, and after one strong performance in Kansas City began his nosedive.

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Overall he pitched to a 13.73 ERA in the second half before accepting his minor league assignment.

“As long as I am healthy and can pitch my pitches, pitch to my ability, I think the results come along with that,” Senga said. “So, I am striving for that and that is what I’m here to do. I came from Japan to the States to do that. Things aren’t always going to go my way, but if that happens, I will grind out there and hopefully the results come.”

Kodai Senga works on pick off drills without a ball during Spring Training at Clover Field, Wednesday, Feb. 25, 2026, in Port St. Lucie, FL. Corey Sipkin for the NY POST

The Mets saw the best of Senga in his rookie 2023 season, when he pitched to a 2.98 ERA and struck out 202 batters in 166 ¹/₃ innings. But injuries limited Senga to one regular-season start the next year, although he started twice during the playoffs.

Senga, before he left camp, was asked what he was still perfecting.

“The forkball, making sure it’s down,” Senga said of his signature ghost fork. “I don’t want to leave it up. It’s still happening a little bit and … hopefully I can bury it in the dirt.”

Manager Carlos Mendoza has been consistent in his praise of Senga since the pitcher’s first start this spring.

“I am excited because of what he’s shown in spring training,” Mendoza said. “The way he threw the ball, how he bounced back, just the smile on his face, the interaction that I’m having with him.”