Frankie Montas has not been considered a reliever since he was an Oakland Athletics rookie in 2017. Yet that's what New York Mets manager Carlos Mendoza declared on Tuesday that Montas will be for the rest of this season.

"We had that conversation today," Mendoza said. "He's going to throw his side (session) and then the first day he will be available is Thursday."

Montas, 32, who signed a two-year, $34 million contract in December to bolster the Mets' rotation, made his second relief appearance since 2018 on Sunday. He surrendered three runs (one earned) on three hits over three innings as the Mets dropped a 7-4 decision to the Milwaukee Brewers for their seventh loss in a year.

"I thought I threw the ball pretty good today," Montas told reporters after his stint that also included two walks and three strikeouts. "I thought I was making more pitches today. I thought I was attacking the zone."

Montas didn't make his season debut until June 24 due a lat strain sustained in spring traianing.

He's compiled a 3-2 record with a 6.38 ERA in eight appearances (seven starts). He has fanned 32 batters in 36 2/3 innings, but surrendered 45 hits and 12 walks for his worst WHIP (1.555) since he pitched exclusively in relief for the 2017 Athletics.

For his career, Montas owns a 47-48 record and a 4.19 ERA. He has made 136 starts and 32 relief appearances for the Chicago White Sox (2015), Athletics (2017-22), New York Yankees (2022-23), Cincinnati Reds (2024), Milwaukee Brewers (2024) and Mets.

Mendoza said the Mets have not decided who will fill Montas' spot in the rotation when it comes up Saturday against the Seattle Mariners, but admitted it could be someone currently pitching for Triple-A Syracuse. Veteran right-hander Paul Blackburn (5-1, 2.55) is on a rehab assignment there and has forged a 3-0 record with a 2.42 ERA in four starts since July 22.

Nolan McLean (5-4, 2.78) and Brandon Sproat (7-5, 4.10) are considered the top prospects in Syracuse's rotation. Neither 24-year-old right-hander has appeared in a major league game.