Mariners trade Luis Castillo to White Sox for 3-player haul
The M's are receiving reliever Seranthony Domínguez, outfielder Nolan Jones and catching prospect Boston Smith.
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After weeks of speculation that his time in the Pacific Northwest was nearing its end, the Seattle Mariners are trading Luis Castillo to the Chicago White Sox.
The M’s are receiving reliever Seranthony Domínguez, outfielder Nolan Jones, catching prospect Boston Smith and cash in exchange for the three-time All-Star.
By moving on from Castillo, the Mariners are saying good-bye to a pitcher who made a major impact during a stint that spanned five seasons in Seattle.
The M’s acquired the right-hander from the Cincinnati Reds just before the 2022 trade deadline. His addition helped push the club over the top to clinch its first playoff berth in 21 years. Castillo posted a 4-2 record and 3.17 ERA with 77 strikeouts over 65 1/3 innings in 11 starts after the trade.
Castillo then pitched in the Mariners’ first playoff game and delivered a dazzling performance, shutting down Toronto over 7 1/3 scoreless innings for the franchise’s first playoff win in a generation.
Castillo, known also as his nickname “La Piedra” (The Rock), went on to earn an All-Star selection and finish fifth in AL Cy Young voting during a 14-win campaign in 2023. He remained a key cog in the club’s rotation into this season.
However, the 33 year old has had a steep decline in production in 2026, posting a 3-9 record with a 5.06 ERA in 99 2/3 innings over 20 appearances (17 starts) following a rough start to this season. He had been better of late, going 2-3 with a 3.88 ERA in 53 1/3 innings over 10 outings (eight starts).
The Bani, Dominican Republic, native finished his Mariners career with a 43-40 record and 3.69 ERA over 718 innings pitched.
“’The Rock’ has been an integral part of this era of our organization’s history,” Mariners president of baseball operations Jerry Dipoto said in a release from the team. “His arrival, and subsequent performance in 2022 set the tone for what has been a fantastic run as a Mariner. We all appreciate everything he has done in Seattle and wish him continued success in all he does.”
Castillo is under contract through next season when he is due to make $24.15 million and has a $25 million vesting option for 2028 if he pitches at least 180 innings ’27. ESPN’s Alden González reported the White Sox will take on the rest of the money on Castillo’s contract.
The haul the Mariners acquired addresses their need for a bullpen arm while adding some buy-low insurance with upside in the outfield with MLB experience and an intriguing catching prospect who is having a breakout year.
Domínguez, 31, has several years of high-leverage experience and a career 3.57 ERA with 52 saves over his eight years in the majors. He has a 4.10 ERA and 4-3 record with 12 saves, 45 strikeouts and 23 walks in 37 1/3 innings over 42 outings this year.
The hard-throwing right-hander features a five-pitch mix with a four-seamer, sinker, sweeper, splitter and curveball. His fastballs average 97.3 mph, and he’s held opponents to a .111 average while racking up a 51.1% whiff rate on his splitter.
Domínguez is set to make $10.5 million in 2027 and has a mutual option for the 2028 season at $12 million, which includes a $2 million buyout.
Coincidentally, Mariners fans might remember Domínguez best for one of his worst moments in the majors. He was the Toronto pitcher who allowed Eugenio Suárez’s go-ahead grand slam during Game 5 of the AL Championship Series last season.
Jones, a 28-year-old lefty bat, has mostly played in the corner outfield spots. He has four years of big-league experience and finished fourth in NL Rookie of the Year voting with the Colorado Rockies in 2023, but the former second-round pick has struggled to replicate that success in the years since and spent all of this season in Triple-A.
Jones is batting .257 with an .807 OPS, 14 homers and 15 doubles in 90 games in the minors this season. He was also traded from Cleveland to Chicago on June 11.
During his breakout 2023 season in Colorado, Jones batted .297 with a .931 OPS, 20 homers, 22 doubles and 20 stolen bases while posting 4.3 bWAR in 106 games. He posted negative bWAR in each of the next two seasons, which included batting .211 with a .600 OPS and five homers in 135 games for Cleveland last year.
Smith, 23, was ranked as the No. 15 prospect in the Chicago’s farm system, per MLB Pipeline. The 2025 sixth-round draft pick is batting .291 with a 1.037 OPS and 22 homers in 78 games across three levels of the minors. He is currently in Double-A.
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Comments
2 Comments
Now the M's should send Colt Emerson down to AAA for more seasoning and a re-set, put Donovan at 3B, say thanks for your service to Garver and bring up .320 hitting Jhonny Pereda at C, and say thanks for your service to Refsnyder and start using Victor Robles at the RH DH position.
Can't believe Dipoto was able to move Castillo without paying a huge amount of his salary AND get a high-leverage relief pitcher in the deal. And Boston Smith is a fast-rising 23 year old who plays 3B as well as C and OF, so the M's just made a move to solidify the 3B weakness in our prospect system. M's have placed him at #14 in their system already!
Nolan Jones is likely forever a 4-A player, good enough for good numbers in AAA, but not quite good enough to land a spot in MLB. His best numbers were in Colorado, which should keep anyone from getting too excited about his offense.