Right-hander Bryce Miller will make his Mariners season debut on Wednesday against the Astros, reports Ryan Divish of the Seattle Times. Miller opened the year on the injured list after straining an oblique in the spring. Divish adds that Seattle will initially go to a six-man rotation, then potentially move to a piggyback situation with Miller and right-hander Luis Castillo.
Injuries have derailed Miller in back-to-back seasons. An elbow issue slowed him for much of 2025. The righty first went on the IL with elbow inflammation in mid-May, but returned after less than three weeks. He made two starts, then went right back on the injured list. Miller came back in August. He remained healthy to close the year and contributed some important innings in the postseason.
Miller made it through just one Spring Training appearance before going down with the oblique injury. His absence opened the door for Emerson Hancock. The former prospect has had chances in the rotation in recent seasons, but they have never amounted to much success. Hancock had a 4.50 ERA or worse in each of his three years as an occasional member of Seattle’s staff.
The 2026 campaign has been a complete reversal for the 26-year-old Hancock. He’s been one of the more surprising breakouts of the young season. Hancock had a mid-2.00s ERA with more than a strikeout per inning heading into Friday’s outing against the White Sox. He allowed five earned runs over six innings in Chicago, but still emerged with his third win. MLBTR’s Steve Adams dug into Hancock’s stellar season in this article for Front Office subscribers.
A decision on Hancock and the rest of the rotation was coming as Miller neared his return. Instead of bumping Hancock or the struggling Castillo, Seattle is keeping everyone in the mix, at least for now. As Divish points out, the club doesn’t have an off day until May 21. Rolling with a six-man rotation will afford the group some extra rest during an arduous stretch of the calendar.
By performance, Castillo deserves to be booted from the group. The righty tossed six scoreless innings against the Yankees in his season debut. Since then, he’s been crushed for 24 earned runs over six outings. Castillo ranks in the fourth percentile for average exit velocity and in the seventh percentile for hard-hit rate. The 33-year-old might be hitting the wall at this stage of his career. Castillo is still due $22.75MM next season, plus $25MM in 2028 if certain thresholds are met, so Seattle is incentivized to find a way for him to add value. The piggyback setup with Miller might help Castillo get back on track.
Photo courtesy of Rick Scuteri, Imagn Images
Looking forward to Miller’s return! As for Castillo, he should be moved to the bullpen.