Eric Chavez didn’t even work a game as an assistant hitting coach for the Yankees, but now he is headed across town for a promotion. 

The former slugger has agreed to join new manager Buck Showalter’s staff with the Mets, as hitting coach, according to a source. MLB.com first reported Chavez’s departure from the Yankees for the Mets on Thursday. 

The Yankees hired Chavez last month as assistant hitting coach, only days after Showalter’s arrival as Mets manager. Teams generally allow coaches to leave for a promotion. 

Chavez, 44, has a close working relationship with Mets general manager Billy Eppler from their time together in The Bronx, as player and assistant general manager, respectively. Eppler, as Angels GM, hired Chavez as a special assistant before installing him briefly as the Triple-A manager. Chavez later returned to the Angels’ front office. 

Chavez played 17 seasons in the big leagues, mostly with the Athletics, and hit 260 career homers. He won six Gold Gloves at third base before injuries later in his career limited his playing time. Chavez spent 2011-12 with the Yankees before finishing his career with the Diamondbacks for two seasons. 

The Yankees had planned to use Chavez as a “Swiss Army knife” in a variety of capacities with the team, according to manager Aaron Boone. Officially, Chavez was to serve as an assistant hitting coach, with Casey Dykes, under new hitting coach Dillon Lawson, who recently replaced Marcus Thames in that position. 

The hiring moves the Mets closer to filling out a staff that will include Joey Cora as the third-base coach and Wayne Kirby as first-base coach. In addition, Jeremy Hefner is returning as pitching coach. Cora spent the last five seasons as Pirates third-base coach and Kirby, who played for the Mets in 1998, was part of Showalter’s coaching staff in Baltimore. 

It’s possible the Mets will employ as many as three hitting coaches this season. This past May, the team fired hitting coach Chili Davis and his assistant, Tom Slater, replacing them with Hugh Quattlebaum and Kevin Howard. After the season, Howard was reassigned to player development. Quattlebaum remains in the organization as the director of hitting development. 

In addition to filling out the hitting staff, the Mets have vacancies to fill at bench coach and in the bullpen. For the bench, team officials have shown interest in Dodgers first-base coach Clayton McCullough, who interviewed last month for the Mets’ managerial opening, but it’s possible he would prefer to remain in Los Angeles.