Mark J. Rebilas-Imagn Images

Mets Acquire Jose Castillo from Diamondbacks: What to Make of Move

Originally posted on New Baseball Media
By Chris Studley | Last updated May 16, 2025 1:19 PM ET

Just days after the Diamondbacks DFA’d reliever Jose Castillo, the Mets picked him up via trade. It’s a depth move, one that gives the Mets more options for their bullpen as the team is down two notable left-handed relievers.

A Look at Castillo

Seven years ago, Jose Castillo had success at the MLB level, as he struck out 52 over 38 frames with the Padres as a 22-year-old. Since then, Castillo shuffled between the Padres, Marlins, and, most recently, the Diamondbacks. The 29-year-old pitched mostly in Reno (AAA) last season but spent some time with the big club in 2024 and 2025.

Castillo got hit around with the D-Backs this season, as he gave up eight earned runs over 6.1 IP. It came amidst Arizona having trouble getting production from their bullpen for myriad reasons. A.J. Puk and Justin Martinez are hurt, while former All-Star Joe Mantiply got shelled before being demoted to Reno.

The Diamondbacks DFA’d Castillo on May 12.

Castillo is a heavy ground ball pitcher, thanks to his sinker/slider combo. It’s different from what Castillo was working with years back with the Padres, when he leaned heavily on a four-seamer.

His sinker does have above-average induced movement (1.7” better than league average), and has depth on the slider. There is deception with the delivery, as Castillo hides the ball well in his motion.

Command hasn’t been a strong suit for Castillo. He held a high BB/9 rate in 2023 (5.7) in the Padres & Marlins farm systems, with those numbers coming down slightly over the years. However, keeping the two-seamer down has not been a strong suit, as several of the hits he gave up with Arizona were elevated in the upper half of the zone.

Per the team, the Mets acquired Jose Castillo for cash considerations. New York (NL) DFA’d reliever Kevin Herget as a corresponding move.

We have acquired LHP Jose Castillo from Arizona in exchange for cash considerations.

In a corresponding move, RHP Kevin Herget has been designated for assignment.
— New York Mets (@Mets) May 16, 2025

Analysis

Don’t think too hard about this move.

The Mets have one left-handed reliever on their roster right now: Genesis Cabrera. AJ. Minter is out for the rest of this season, while Brooks Raley won’t be an option until later in the 2025 campaign.

It’s a depth move for the Mets, one that, on paper, gives the team a nice depth matchup option against lefties.

This article first appeared on New Baseball Media and was syndicated with permission.

More must-reads: