With a pair of rookie outfielders already thriving, the New York Mets are set to promote outfield prospect Nick Morabito, who can play all three spots, from Triple A, league sources told The Athletic on Tuesday.

After their wild win over the Washington Nationals on Monday, the Mets planned to designate outfielder Austin Slater for assignment, league sources confirmed. The New York Post first reported the decision. Morabito, already on the 40-man, would replace him on the active roster.

With lefty prospect Zach Thornton set to pitch in Wednesday’s game, the Mets needed to eventually clear a 40-man roster spot.

In 175 plate appearances at Triple A this season, Morabito, the Mets’ No. 10 prospect in Keith Law’s organizational ranking for The Athletic, holds a .755 OPS with four home runs and 14 stolen bases. The right-handed batter performed well in the Arizona Fall League after last season, posting a .914 OPS in 80 plate appearances. He was eligible for the Rule 5 draft in the offseason before the Mets put him on the 40-man roster.

Joining the team in Washington, D.C., would be a homecoming for Morabito, who was drafted in the second round out of Gonzaga College High in 2022.

The scope of Morabito’s role is unclear but the expectation is that he will at least play against some left-handed pitchers. At a minimum, it could be a decent time for Morabito to get at least a taste of the majors.

The Mets’ outfield already features Juan Soto, A.J. Ewing and Carson Benge. The Mets called up Ewing last week. Over his first 25 plate appearances, Ewing owns a .500 on-base percentage. Benge won a job out of spring training and, after a slow start, has a .853 OPS in May.

Over the last week or so, New York (21-26) has played its best baseball of the season, winning six of their last seven games.