The Mets have made room for the return of Fernando Salas to the roster. Jon Heyman has reported that the Mets are trading Gabriel Ynoa to the Baltimore Orioles in exchange for cash. This is likely the move that will open up a roster spot on the 40-man.
The 40-man roster is a list of players that are eligible to be added to the 25-man roster (active roster). Also, any player who is going to participate in the postseason needs to be on the 40-man by August 31st to be eligible.
Ynoa, 23, made 10 appearances with the Mets in 2016 and started 3 games. He was 1-0 with a 6.38 ERA in 18.1 innings pitched. Ynoa is a player that the Mets seem to think has some upside, however this move is understandable given the Mets depth in the starting rotation.
orioles acquire young pitcher gabriel ynoa from mets for cash
— Jon Heyman (@JonHeyman) February 10, 2017