The fit is not exactly clear, but the Mets will create room for Mark Vientos’ bat.

The Mets called up the top prospect from Triple-A Syracuse ahead of Wednesday’s game at Citi Field against the Rays.

Vientos is starting at third base and batting eighth.

The Mets have averaged the eighth-fewest runs in MLB and been devoid of power, recently going 56 straight innings without a home run.

They hope Vientos’ bat can serve as a jolt for an offense that also includes rookies Francisco Alvarez and Brett Baty.

The Mets sent Luis Guillorme down to Triple-A to make room for Vientos.

Vientos, a 23-year-old who briefly debuted last year, posted a 1.104 OPS with 13 home runs in 38 games at Syracuse.

He had been playing first and third base and will bring a poor defensive reputation to the majors, where his playing time will be a curiosity.

Pete Alonso is entrenched at first base, and Baty — sometimes spelled by Eduardo Escobar against lefties — has played well at third base.

The Mets have opted for a platoon at designated hitter in which lefty-hitting Daniel Vogelbach has hit righties well (against whom he has a .404 on-base percentage but with just two homers) and righty-hitting Tommy Pham has not found results.

Pham is hitting just .188 with three home runs, but many hard-hit balls have not found grass.

Last year, Vientos was called up as a possible platoon DH bat against lefties and did not distinguish himself in 16 games.

This year, he has crushed everyone — righties and lefties — in the minor leagues.

There is no obvious role for him with the Mets, but their struggling offense could not ignore him any longer.

“He’s doing fine,” manager Buck Showalter said Monday. “He has to master that level. He’s working and getting a chance to play third base a lot with Brett not there. He is improving there.”