Luis Castillo and His Fastball Heat Up as the Trade Deadline Approaches

With the All-Star break in the rear-view mirror, the eyes of the baseball world turn to the upcoming trade deadline, which is now less than two weeks away. Juan Soto’s sudden availability is dominating the headlines, pushing the rest of the field to the back burner with the focus on the possible blockbuster deal. Still, for the majority of teams who are priced out of the Soto sweepstakes, there’s no shortage of interesting trade candidates to go after over the next few weeks.
For teams looking for pitching help, the top option on the market is almost certainly Luis Castillo. A pair of shoulder injuries to the two other top targets has thrown a wrench into the market; Frankie Montas threw three innings yesterday in his first start since July 3, and Tyler Mahle is scheduled to make his first start off the IL on Sunday. It’s certainly possible either Montas or Mahle (or both) will be dealt in the next few weeks, but teams will understandably be more cautious with them.
Castillo dealt with his own shoulder injury this spring which held him back from making his season debut until May. He wasn’t all that sharp through his first four starts, but he’s turned it on since then, averaging more than six innings per start since and allowing just three total runs across his last four turns. During this recent hot streak, he’s struck out 33 batters (a 30.8% strikeout rate) in 27 innings. In his final start before the midseason break, Castillo held the Yankees to a single run in seven innings, allowing two hits and four walks and striking out eight.
Well known for his fantastic changeup, that pitch hasn’t been nearly as effective as it has been in the past. Over the first five seasons of his career, he ran a 41.2% whiff rate with the pitch, the fifth-highest whiff mark for a changeup during that period. This year, that has fallen to just 25.1%, a career low and the third year in a row it’s dropped. It’s still an effective pitch at limiting hard contact (.305 xwOBAcon), but batters simply aren’t swinging and missing at it as much as they used to.
To combat the slow decline of his changeup, Castillo has turned to his four-seam fastball, throwing his heater more often than his cambio for the first time since 2018:
It’s still a bit of a surprise to see him turn away from his changeup despite its lackluster results this year. That pitch has been such a dominant weapon for him, and he’s relied on it as his primary out pitch for the last three seasons. The biggest reason why he’s turned away from it, though, isn’t because of its loss of effectiveness; it’s because his four-seamer has been better than ever before. Read the rest of this entry »