ATLANTA -- The Mets will be without their ace for quite a while yet.

The team on Wednesday transferred Kodai Senga from the 15- to the 60-day injured list to clear 40-man roster space for Tyler Jay, a reliever they called to the active roster. Senga, who recently began throwing off flat ground during his rehab from a strained posterior capsule in his right shoulder, is not eligible to return from the IL until May 27.

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¡°From the beginning, we knew it was going to take time,¡± Mets manager Carlos Mendoza said. ¡°We¡¯ve been slow playing it from the beginning. We took that extra couple of weeks before he started playing catch in Spring Training. There¡¯s nothing new to it. It¡¯s just more where we¡¯re at, where he¡¯s at.¡±

The benefit of shifting a player from the 15- to the 60-day IL is that Senga no longer counts against the 40-man roster limit.

Senga, 31, has been sidelined since early Spring Training due to a shoulder capsule strain. He went about a month without throwing at all before graduating to a flat-ground throwing program in late March. But Senga has yet to throw off a mound. Even once he does, he will need to progress through a series of bullpen sessions, live BP sessions and eventually game action. The Mets also intend to space out Senga¡¯s rehab starts, regularly giving him an extra day of rest.

¡°Not a setback. Nothing wrong with him,¡± Mendoza said. ¡°We just knew it was going to take some time. With him still throwing flat grounds and things like that -- he hasn¡¯t even gotten on a mound -- it¡¯s going to be a few weeks before we see him. So that was the move.¡±

Although Senga is eligible to return on May 27, no guarantees exist that he will do so at that time. Much will depend upon the speed of his rehab process.

¡°It¡¯s too early to tell,¡± Mendoza said. ¡°He still hasn¡¯t even touched the mound. We still have to clear some hurdles here.¡±

The team¡¯s best pitcher last year, Senga went 12-7 with a 2.98 ERA and 202 strikeouts during his first season in the big leagues. Prior to that, he was an ace pitcher over 11 seasons in Japan, earning himself a five-year, $75 million contract with New York in 2022. Of note, Senga can opt out of his contract following the '25 season if he accumulates at least 233 2/3 innings before that time.