D-backs Face Difficult Decision on Miguel Castro

The Diamondbacks find themselves in a difficult situation with Miguel Castro. Castro signed a one-year deal with a $5 million option for 2024 that vests after 60 appearances. Castro has appeared in 57 games for the D-backs this season, going 5-6 with a 5.19 ERA. In back-to-back games he's allowed four runs, taking a blown save on Wednesday and a loss last night. With just three appearances to go until the option vests, the team faces a difficult decision on what to do with the struggling reliever.

In his first 27 appearances, Castro delivered scoreless outings in 24 (89%) while posting an excellent 2.13 ERA. Towards the end of that run, the team entrusted him to be the closer. Then a poor outing against the Braves, in which he allowed a go-ahead grand slam to Eddie Rosario, started what was a troubling trend for the 28-year-old right-hander. In his last 30 outings, Castro has an 8.28 ERA and allowed seven home runs while only holding opponents scoreless in 20 (67%). At best you can chalk that up to inconsistency, but it could spell a potential problem that could not only prevent them from making a run this year, but also next.

The question becomes what happens if the D-backs elect to cut bait. The ideal situation is someone claims him off waivers and assumes the rest of that contract, but that situation is very unlikely. Should Castro be designated and placed on release waivers, it's likely he goes unclaimed. If that comes to pass, the D-backs would be responsible for the rest of the contract minus a prorated version of the league minimum for 2023. 

The option becomes tricky, as there's no clarification on how that would play out if Castro signs with another team and makes three appearances. If it vests, the D-backs could end up being responsible for almost all of the $5 million he's owed. That in itself could play into the sunk cost fallacy, as the team could elect to keep Castro for the 2024 season and see if they can get more consistency with him.

It's going to be difficult for the D-backs to get much more out of Castro in his Age 29 season. Over the last three seasons his K-BB%, which measures the difference between strikeout and walk rates by the percent, has been around 11-12% the past three seasons. Over that stretch he has an ERA of 4.15, although when adjusting for the ballparks he's pitched in and the leagues it's an ERA+ of 99. Despite being able to touch 98 MPH on his sinker, the lack of consist command of his slider in games has contributed  to why he's bounced around from team to team over the past five years.