The Mets optioned Melendez to Triple-A Syracuse on Tuesday.
The 27-year-old joined the Mets on a one-year, $1.5 million contract in February after being non-tendered by the Royals at the start of the offseason. Melendez went 4-for-11 with two homers in his four spring games with the Mets but struggled for Team Puerto Rico in the World Baseball Classic, going 0-for-4 with two walks and two strikeouts. He could be up with the Mets at some point this season.