To make room for lefty reliever Jose Castillo, the Mets have optioned Dedniel Núñez back to Triple-A Syracuse, league sources say.
Núñez, who emerged as a high-leverage arm last season before suffering an elbow injury, made his season debut on May 5. The Mets planned for Núñez to remain with the team long term, but he walked six batters in 3.2 innings.
The Mets had been looking for another lefty reliever since losing both A.J. Minter and Danny Young for the season. In making the move for Castillo, it was easier to option Núñez than designate Genesis Cabrera for assignment and risk losing him.