White Sox Move Luis Castillo To Bullpen

The White Sox will use Luis Castillo out of the bullpen, manager Will Venable told reporters on Thursday (link via Jesse Rogers of ESPN). Rookie David Sandlin will start tomorrow against Detroit. Chicago acquired Castillo from Seattle at the deadline. It was their biggest move to address a rotation that was the team’s clearest weakness. The Sox parted with a mid-tier prospect, catcher/outfielder Boston Smith, but placed a decent financial bet on Castillo stabilizing the rotation. They assumed roughly $15MM in the difference between Castillo’s contract and that of reliever Seranthony Domínguez — whom they sent back to the Mariners as a salary offset. Castillo was the odd man out in a crowded Seattle rotation but provided plenty of experience the White Sox’ staff was lacking. He was rocked for five runs in four innings against Tampa Bay in his team debut. Castillo rebounded with his best outing of the season against Cincinnati, firing seven scoreless frames with 10 strikeouts. That apparently said more about the Reds’ offense, as he has been unable to complete five innings in any appearance since then. Opposing lineups blitzed Castillo for 18 runs across 15 1/3 innings over his next four starts. The Sox tried mitigating the issue by using Sean Newcomb as an opener against St. Louis last weekend. It didn’t help, as he allowed another three runs on four hits and three walks in just 2 2/3 frames. General manager Chris Getz didn’t pull any punches when discussing Castillo’s performance earlier this week. “The quality of pitches has definitely gone in the wrong direction,” the GM said on Monday (relayed by Brian Dulik of MLB.com). “We’ve got to solve it. … It has been surprising.” There’s some truth to that. Castillo’s velocity is down across the board this month, with the dip in his four-seam fastball the most jarring. He’s averaging 93.2 mph on that pitch in September; it was in the 95-96 range throughout the season. He has also lost 1-2 ticks on his sinker, slider, and changeup. There’s been a corresponding drop in the spin rate on his four-seamer. All that said, Castillo’s struggles didn’t come out of nowhere. He was already amidst the worst season of his career with Seattle. The three-time All-Star had a 5.04 ERA with a diminished 19.4% strikeout rate over 20 appearances for the Mariners. It was something of a reclamation play even at the time of the trade. Chicago won tonight’s series opener. Erick Fedde and a trio of relievers — Bryan Hudson, Jordan Hicks and Grant Taylor — held the Tigers to one run. That brought Chicago to 78-75 and back into first place in the AL Central. They hold the tiebreaker over the Guardians, who entered the day with a half-game lead and were idle. The Sox play three more against Detroit and will close the regular season with very winnable series against Kansas City and Colorado. Cleveland is back into the final Wild Card spot, holding a two-game edge on the Rangers and Blue Jays. The White Sox are one game ahead of the Astros for the #2 seed and associated first-round bye. There’s a path for all those teams to secure a trip to the ALCS. The playoff format all but ensures that only one of the American League’s three best teams — the Rays, Yankees and Red Sox — will advance beyond the Division Series. It’s the biggest storyline of the regular season’s final 10 days. Sandlin, who has a 5.64 ERA in his first six career appearances, will start at least one of those pivotal games. Sean Burke and Davis Martin will round out the weekend. The Sox haven’t announced any plans beyond that but will presumably go to Anthony Kay and Fedde for two of the starts against Kansas City. It’s to be determined if Sandlin will get another turn or they’ll try to bullpen their way through the fifth spot. Burke and Martin are their top two starters on paper, yet neither has been at peak form in recent weeks. There’s no way around the pitching woes for this postseason, but the Sox should be among the most motivated teams in the offseason rotation market. Castillo is signed for $22.75MM next year.