Clay Holmes pitches for the Yankees against the Los Angeles Dodgers...

Clay Holmes pitches for the Yankees against the Los Angeles Dodgers in Game 4 of the World Series at Yankee Stadium on Tuesday, Oct. 29, 2024. Credit: Jim McIsaac

Add another name to the Mets’ growing list of pitchers who are projects.

They have agreed to a three-year, $38 million contract with former Yankees closer Clay Holmes, pending a physical, sources confirmed Friday night.

The Mets plan to try to make Holmes a starting pitcher, according to a person familiar with their plans. If that doesn’t work, he can return to being a high-leverage reliever — a setup man for and backup to closer Edwin Diaz — as he was in recent years with the Yankees.

Holmes joins Frankie Montas (two years and $34 million) as recent additions to the 2025 rotation. Kodai Senga and David Peterson are penciled-in holdovers. Paul Blackburn, Tylor Megill and Jose Butto also are internal options.

The Mets still could stand to bring in another starter, though it won’t necessarily be the bona fide ace they lack. Righthander Corbin Burnes and lefthander Max Fried are the top starters still available on the free-agent market.

Holmes’ deal is the largest financial guarantee by the Mets in their year-plus under president of baseball operations David Stearns, supplanting Montas’ pact from earlier this week.

Attempting to turn Holmes, who will turn 32 on Opening Day, into a starting pitcher is in line with the Mets’ philosophy under Stearns to find good values to fill out the rotation. Although Holmes has been a reliever for virtually his entire major-league career, he rose through the minor leagues as a starter.

If the conversion is successful, Holmes’ average annual salary of about $13 million will be cheap for a starting pitcher, especially in the context of the red-hot pitching market this offseason. If the conversion is not successful, $13 million is an expensive but tolerable salary for a high-end reliever, especially for a team owned by multibillionaire Steve Cohen.

Among the reasons for the Mets’ confidence in this experiment: They showed most recently in 2024 — with starters Luis Severino and Sean Manaea, relievers Reed Garrett and Dedniel Nunez and others — that with pitching coach Jeremy Hefner and their modernized, high-tech pitching department, they are able to help pitchers make the most of their abilities, in some cases turning relative nobodies into legitimate contributors.

An extra layer heading into 2025: The Mets hired Yankees assistant pitching coach Desi Druschel for the same role. He especially is familiar with Holmes’ talent, repertoire, demeanor, work ethic and other variables that will determine whether his switch to the rotation works out.

Holmes played for the Yankees the past four seasons, joining them as an under-the-radar trade pickup in 2021. He became their closer in 2022, made the All-Star team twice and overall had a 2.69 ERA, a 1.12 WHIP and more than a strikeout per inning.

His most recent season was his worst. His ERA bumped up to 3.14 and his WHIP rose to 1.30. He blew 13 save opportunities and lost his closer job in September.

Holmes remained a late-inning option for manager Aaron Boone, however, including in the postseason, when he made 13 appearances and had a 2.25 ERA.

With Holmes, the Mets are jumping on a recent trend to try highly effective relievers in larger roles.

Former Mets bullpen standout Seth Lugo did the same upon becoming a free agent, turning a rotation tryout with the Padres in 2023 into a three-year, $45 million deal with the Royals. He finished second in the AL Cy Young Award voting in 2024.

In the NL East, Atlanta took a shot on Reynaldo Lopez, who was a mostly ineffective starter early in his career, got demoted to the bullpen, found success and signed as a starter again last offseason. He was an All-Star with a 1.99 ERA in his first season with Atlanta.

Former Yankee Michael King, who was effective and versatile while working primarily as a bullpen piece for several years, made the jump back to starting with the Padres last season, posting a 2.95 ERA across 173 innings.

Workload will be among the biggest questions for Holmes and the Mets. He totaled 75 innings (including the postseason) in 2024, his most ever in the majors.

He hasn’t reached triple-digits since 2018, when he pitched 101 1⁄3, mostly at Triple-A. His most as a pro were the 136 1⁄3 in Double-A in 2016.