The Mets have designated infielder Diego Castillo for assignment, tweets Will Sammon of the Athletic. That clears the necessary 40-man roster spot for left-hander Sean Manaea, whose two-year deal was finalized.
New York claimed Castillo off waivers from the Diamondbacks a week ago. It might prove an exceedingly brief stay in the organization for the right-handed hitter. The Mets will have to trade Castillo or put him on waivers themselves within the next seven days.
The 26-year-old spent almost all of last season in Triple-A. Arizona acquired Castillo in a minor trade with the Pirates over the 2022-23 offseason. They kept him on optional assignment to their top affiliate in Reno for all but one game. The 5’10” middle infielder had a solid year for the Aces, hitting .313/.431/.410 through 556 plate appearances. Castillo only hit three home runs in a very favorable offensive environment, but he demonstrated strong strike zone discipline. He walked at a massive 17.4% rate while striking out just 14.2% of the time.
It was a reversal from his 2022 MLB work in Pittsburgh. Castillo connected on 11 homers in 283 plate appearances (roughly half a season) as a rookie. He hit .206 with a meager .251 on-base percentage in that time, largely because of a poor strikeout and walk profile. Castillo walked less than 5% of the time while striking out in nearly 27% of his plate appearances as a big leaguer.
Castillo has been more of a hit-over-power player over an eight-year professional career. He’s a .276/.346/.373 hitter in the minors. He spent the bulk of that time in the Yankees system before being traded to Pittsburgh in what turned out to be a lopsided 2021 deal sending Clay Holmes to the Bronx.