Mariners' Luis Castillo: Working behind Miller on Sunday
Rotowire
Castillo is slated to work out of the bullpen and will piggyback starter Bryce Miller during Sunday's game against the Diamondbacks in Seattle, Adam Jude of The Seattle Times reports.
Though both Castillo and Miller have expressed a reluctance to being used in a piggyback arrangement, the two pitchers will nonetheless operate in a tandem for a third consecutive turn through the rotation. The setup worked well the last time out Monday in Sacramento, with Castillo starting the game and delivering one of his better efforts of the season, as he struck out six and allowed just two hits and two walks over four scoreless frames. Miller followed with five innings of two-run ball and was credited with the win, but Castillo should have better odds of factoring into the decision Sunday while he and Miller are used in the opposite order. The Mariners will reassess their rotation plans after Sunday's contest, and Castillo may need another strong showing against Arizona to ensure that he avoids moving into a full-time relief role.
... See More... See Less
Mariners' Luis Castillo: Excellent as opener
Rotowire
Castillo allowed two hits and issued two walks while striking out six batters over four scoreless innings in a no-decision against the Athletics on Monday.
After struggling mightily as a traditional starter this season, Castillo was deployed out of the bullpen for the first time in his career in his previous appearance May 19. The veteran righty was then moved back into a starting role Monday, but the plan all along was to pair him with Bryce Miller. Castillo ended up thriving with that setup, holding the A's to just two hits while racking up 12 whiffs and six punchouts over four frames. He was pulled after 68 pitches in favor of Miller, who fared well himself in closing out the contest by giving up two runs over five innings. It remains to be seen how Seattle will use Castillo going forward, but he made a case to remain a starter -- at least as part of a tandem -- with his performance Monday. Of course, it will dampen his fantasy value considerably if he's limited to fewer than five innings and 70 pitches as he was against the A's.
... See More... See Less
Mariners' Luis Castillo: Starting in pairing with Miller
Rotowire
Mariners manager Dan Wilson said that Castillo will start Monday's game against the Athletics in Sacramento and will be used as part of a tandem with Bryce Miller, Ryan Divish of The Seattle Times reports.
In his last appearance Tuesday against the White Sox, Castillo pitched in relief for the first time in his 10-year big-league career, covering 2.1 frames and allowing two earned runs behind Miller, who started and worked the first 5.2 innings. The two will be deployed in the opposite order for the upcoming turn through the rotation, and while Castillo should have a higher innings floor as a starter, his poor form of late could result in Wilson leaning on Miller to handle the larger share of the pitching workload. Though the Mariners are taking a fluid approach to the back end of the rotation, Castillo may need a positive showing against the Athletics to avoid a demotion into a more traditional bullpen role. He'll head into Monday's start with a 6.41 ERA and 1.55 WHIP on the season, with both ratios being the worst marks of his career by a considerable margin.
... See More... See Less
Mariners' Luis Castillo: Struggles persist in relief outing
Rotowire
Castillo (1-5) allowed two runs on a hit, two walks and a hit batsman while striking out four over 2.1 innings, taking the loss Tuesday versus the White Sox.
Castillo was fine through two innings, but manager Dan Wilson left him in for the start of the ninth. That ended up being a mistake, and Andres Munoz failed to stop the White Sox's rally after coming in for mop-up duty. Castillo's poor relief outing stands in contrast to a superb start from Bryce Miller, who appears to have bumped Castillo out of the rotation. Castillo is at a 6.41 ERA, 1.55 WHIP and 47:18 K:BB through 46.1 innings over 10 outings (nine starts). It'll likely take an injury to another pitcher for Castillo to get back in the rotation at this point.
... See More... See Less
Mariners' Luis Castillo: Piggybacking Miller on Tuesday
Rotowire
Castillo is slated to piggyback starting pitcher Bryce Miller during Tuesday's game against the White Sox, Adam Jude of The Seattle Times reports.
Castillo will be making the first relief appearance of his MLB career Tuesday after going 1-4 with a 6.34 ERA and 1.57 WHIP through his first nine starts of the season. Since Miller covered 5.1 innings in his 2026 Mariners debut last week in Houston following his return from the injured list, manager Dan Wilson is likely to let Miller work as long as he's effective against the White Sox. With that in mind, Castillo's innings projection for Tuesday is highly variable, and how he and Miller both perform could determine how Seattle sets up its rotation moving forward. If Miller comes through with a strong outing Tuesday, he'll likely draw another start the next time the fifth spot in the rotation comes up, while Castillo could be thrust into a more flexible bullpen role on a longer-term basis.
... See More... See Less
Mariners' Luis Castillo: Tagged with another loss
Rotowire
Castillo (0-4) was tagged with the loss Saturday against the White Sox, allowing four runs on five hits across four frames. He struck out six.
This loss against Chicago ballooned Castillo's woeful ERA to 6.57 across 38.1 innings in eight outings this year. He's lost his past three starts and has given up at least four runs in each of those games. Castillo has been confirmed to start Thursday against the Astros, but according to Ryan Divish of The Seattle Times, after that the Mariners plan to piggyback him with Bryce Miller in the rematch series against the White Sox that runs May 18-20.
... See More... See Less
Mariners' Luis Castillo: Takes another loss
Rotowire
Castillo (0-3) allowed four runs on six hits, two walks and a hit-by-pitch while striking out five over six innings to take the loss Sunday versus the Royals.
Castillo was doing fine until the fourth inning, when he allowed four straight batters to reach base to open the inning. Three of them came around to score, and the Royals tacked on an extra run in the sixth. Castillo has allowed at least four runs in five of his seven starts this season, though this is the third time he's allowed four earned runs. He has a 6.29 ERA, 1.66 WHIP and 31:13 K:BB through 34.1 innings. Until Castillo is able to limit baserunners better, he is likely to continue having trouble preventing runs. His next start is projected to be on the road versus the White Sox.
... See More... See Less
Mariners' Luis Castillo: Fans six in no-decision
Rotowire
Castillo tossed five innings against the Athletics on Tuesday, allowing two runs on five hits and two walks while striking out six batters.
Castillo gave up a run in the first inning and another in the fourth but kept Seattle in the contest throughout his time in the game. The right-hander wasn't very efficient, however, as he needed 95 pitches to complete five frames. That was partly because he had his swing-and-miss stuff working -- Castillo recorded 14 whiffs, and his six punchouts were his second most through five starts so far this season. The veteran hurler is still looking for his first victory, which he'll try to notch in what's projected to be a matchup versus Minnesota on the road his next time out.
... See More... See Less
Mariners' Luis Castillo: Ineffective again Sunday
Rotowire
Castillo allowed seven runs on 10 hits and one walk while striking out three batters over 3.1 innings in a no-decision against Houston on Saturday.
The Mariners gave Castillo a two-run lead in the first inning, but the veteran hurler fell behind when Taylor Trammell cleared the bases with a three-run double in the second. Castillo gave up three more runs in the third and another in the fourth before being pulled with one out in the latter frame. After tossing six scoreless innings against the Yankees in his first start of the campaign, Castillo has surrendered 11 runs (10 earned) over seven frames across his past two outings. He'll try to get back on track in his next start, which lines up to be a road outing in San Diego.
... See More... See Less
Mariners' Luis Castillo: Struggles in no-decision
Rotowire
Castillo did not factor into the decision Sunday against the Angels, allowing four runs (three earned) on six hits and one walk while striking out four over 3.2 innings.
Castillo couldn't find a rhythm in this one, allowing at least two baserunners in every inning he worked and exiting before completing four frames for the first time since 2024. The right-hander ran into trouble immediately, allowing a leadoff double to Zach Neto before Jorge Soler brought him home with an RBI single, and the outing didn't improve much from there. Unlike his dominant Opening Day outing in which he tossed six scoreless innings with seven strikeouts, Castillo failed to fool hitters Sunday and was consistently pitching under pressure. The 33-year-old will look to bounce back in his next scheduled start against Houston, though it presents a tough test against one of the league's most productive offenses early in 2026.
... See More... See Less
Mariners' Luis Castillo: Dominates Yankees, reaches 1500 Ks
Rotowire
Castillo did not factor into the decision Monday against the Yankees, allowing two hits and two walks while striking out seven over six scoreless innings.
Castillo was in complete control, holding the Yankees hitless until the fourth inning and limiting them to just two hits overall. The right-hander generated 17 whiffs and leaned heavily on his primary arsenal, throwing 87 of his 95 pitches as either a fastball or slider. Castillo had hitters fooled all night, but his final strikeout was a milestone moment, as he got Aaron Judge to swing through an inside breaking ball for his 1,500th career strikeout before exiting after the sixth inning. The 33-year-old will look to replicate Monday's success in his next scheduled start against the Angels.
... See More... See Less
Mariners' Luis Castillo: Strong finish to spring slate
Rotowire
Castillo allowed one run on four hits and a walk while striking out five across five innings in Monday's matchup with the Padres.
Castillo finished Cactus League play on a high note, allowing three runs over nine innings in his final two outings. It's certainly an encouraging development after the right-hander struggled to a 27.00 ERA in his first three appearances (six innings). Castillo, who's posted a sub-4.00 ERA in each of his last seven seasons, made a team-high 32 regular-season starts in 2025, finishing with a 3.54 ERA, 1.18 WHIP and 162:46 K:BB across 180.2 innings.
... See More... See Less
Mariners' Luis Castillo: Short outing in ALCS
Rotowire
Castillo (1-1) allowed three earned runs on five hits and one walk while striking out one across 2.1 innings to take the loss in Game 4 of the ALCS on Thursday.
Castillo got through two innings unscathed, but he allowed five of the first six hitters he faced in the third frame to reach base before being pulled. This was Castillo's first stumble of the postseason, as he had previously thrown six scoreless innings across two appearances in the ALDS. He has a less impressive 5:5 K:BB, but he has largely been a reliable arm for Seattle.
... See More... See Less
Mariners' Luis Castillo: Bounces back in ninth win
Rotowire
Castillo (9-8) earned the win over Atlanta on Sunday, allowing one run on four hits and no walks across six innings. He struck out six.
It was a much-needed outing for Castillo, who earned his first win since July 28 -- he'd struggled to a 10.06 ERA in his previous four starts (17 innings). Overall, Castillo's ERA sits at 3.85 on the year with a 1.27 WHIP and 144:44 K:BB through 29 starts (161.1 innings). Castillo will look to build on Saturday's effort his next time out, currently lined up for next week against the Angels.
... See More... See Less
Mariners' Luis Castillo: Skid continues Monday
Rotowire
Castillo (8-8) allowed five runs on six hits and a walk while striking out five over four innings to take the loss versus the Rays on Monday.
Castillo was held under the five-inning mark for the third time in his last four starts. In that span, he's surrendered 19 runs over 17 innings, including six home runs, one of which came off the bat of Nick Fortes in the second inning of Monday's contest. Castillo is also winless in his last six outings, though he's taken just two losses in that span. For the season, he's now at a 3.94 ERA, 1.29 WHIP and 138:44 K:BB through 155.1 innings over 28 starts. He'll look to get back on track over the weekend in a road start at Atlanta.
... See More... See Less
Mariners' Luis Castillo: Ambushed early in no-decision
Rotowire
Castillo did not factor into the decision Tuesday, allowing five runs on five hits and three walks over five innings in a 7-6 loss against San Diego. He struck out six.
Castillo ran into immediate trouble Tuesday, surrendering all five of his earned runs in the first inning, punctuated by a Ramon Laureano grand slam. The 32-year-old hurler has hit a rough patch, pitching to a 5.45 ERA and 1.51 WHIP over 36.1 innings in his past seven starts. He's lined up to next take the mound Monday at Tampa Bay.
... See More... See Less
Mariners' Luis Castillo: Settles for no-decision Friday
Rotowire
Castillo didn't factor into the decision in Friday's 3-2 win over the Rays, giving up two runs on five hits over seven innings. He struck out five without walking a batter.
All the damage off the veteran righty came on solo shots by Brandon Lowe in the first inning and Junior Caminero in the sixth, but all of Seattle's offense came on a three-run blast by Cal Raleigh in the eighth. Castillo delivered his 14th quality start of the year on 99 pitches (72 strikes), and he's allowed three earned runs or fewer in eight straight trips to the mound, posting a 2.25 ERA, 1.02 WHIP and 45:7 K:BB through 48 innings over that span. He'll look to get back in the win column in his next outing, which is scheduled to come on the road next weekend against the Mets.
... See More... See Less
Mariners' Luis Castillo: Labors in no-decision
Rotowire
Castillo did not factor into the decision in Saturday's 6-4 extra-innings loss to the Rangers, allowing two runs on four hits and one walk with four strikeouts over 4.1 innings.
Castillo allowed both of his runs in the third inning and failed to complete five frames for just the second time in 23 starts, throwing only 51 of 87 pitches for strikes. Still, the veteran has now surrendered three earned runs or fewer in seven straight outings, a stretch that includes four wins and four quality starts. He'll take a 3.22 ERA, 1.21 WHIP and 115:37 K:BB across 131.1 innings into a home matchup with the Rays next weekend.
... See More... See Less
Mariners' Luis Castillo: Falls to Milwaukee
Rotowire
Castillo (7-6) took the loss Wednesday against the Brewers, allowing six runs (three earned) on 10 hits over five innings. He struck out seven.
The 10 hits allowed matched a season high for Castillo, who would take his first loss since June 18 -- the right-hander had pitched to a stellar 1.46 ERA in four starts (24.2 innings) prior to Wednesday. Overall, Castillo sports a 3.30 ERA with a 1.24 WHIP and 107:36 K:BB over 21 starts (120 innings) this season. He'll look to get back on track in his next outing, currently scheduled for next week against the A's.
... See More... See Less
Mariners' Luis Castillo: Picks up win in one-sided victory
Rotowire
Castillo (6-5) earned the win Friday, allowing three runs on six hits and two walks over five innings while striking out six in the 12-3 victory over the Tigers.
Castillo shined early, yielding just one earned run through the first five innings before running into trouble opening the sixth, allowing back-to-back hits and another run before being removed with a runner on third. The 32-year-old entered the matchup coming off his best start of the season and has now posted a 3.60 ERA with 33 strikeouts and 11 walks over his last six outings.
