Castillo is slated to make his first start during the Mariners' fifth game of the season Monday versus the Yankees at T-Mobile Park, Adam Jude of The Seattle Times reports.

Emerson Hancock is the Mariners' de facto fifth starter while stepping into the rotation in place of the injured Bryce Miller (oblique), but he'll end up taking the hill for Seattle's fourth game Sunday versus Cleveland while Castillo moves to the back of the schedule. The rotation setup is likely just a means to get Castillo some extra rest after he started the Mariners' spring training finale Monday in San Diego. Castillo covered five innings and tossed 76 pitches in that outing, so he should be ready to handle a relatively normal workload in his 2026 debut.

Fried (1-0) allowed two hits and a walk while striking out four over 6.1 shutout innings to earn the win over the Giants on Wednesday.

The Yankees' second-inning surge on offense was more than enough help for Fried, who looked sharp in the season opener. The southpaw had a 4.40 ERA over 14.1 innings during spring training, but he got on track for the first game that counts. Fried was strong in 2025 with a 2.86 ERA, 1.10 WHIP and 189:51 K:BB over 195.1 innings across 32 regular-season starts and should be the clear ace in the Yankees' rotation until Gerrit Cole (elbow) is able to make his season debut. Fried is tentatively projected to make his second start of the season in Seattle next week, which would be the first of a two-start week as the Yankees are projected to use a four-man rotation to begin the year.

Webb (0-1) took the loss versus the Yankees on Wednesday, allowing seven runs (six earned) on nine hits and a walk while striking out seven over five innings.

Webb was roughed up for five runs in the second inning and gave up two more in the fifth before exiting the game. He threw 58 of 86 pitches for strikes, which was right in line with his workload in his last Cactus League start Thursday. The right-hander is a true workhorse for the Giants, having topped 200 innings in three straight years and 30 starts in each of the last four campaigns. He pitched to a 3.22 ERA, 1.24 WHIP and 224:46 K:BB over 207 innings in 2025 and should continue to eat innings with strong ratios again this season. Webb is tentatively projected to make his second start of the year on the road at San Diego next week.

Rea will make Chicago's Opening Day roster as a long reliever, Jordan Bastian of MLB.com reports.

With Cade Horton staking his claim to a rotation spot after an impressive rookie season and Edward Cabrera joining the Cubs via trade, Rea ultimately got pushed to the bullpen. The veteran righty made 27 starts for Chicago during the 2025 regular season, but he'll now slot in as a long reliever capable of supplying multiple innings out of the bullpen. Rea's fantasy value takes a hit in this role, though he certainly could still make some spot starts throughout the year.

San Diego placed Musgrove (elbow) on the 15-day injured list Wednesday.

After undergoing Tommy John surgery in October 2024, Musgrove missed the entire 2025 season but received full clearance ahead of spring training. However, after Musgrove experienced inflammation in his surgically repaired elbow following an exhibition versus Team Great Britain on March 4, the Padres have elected to tread carefully with the veteran righty. Musgrove has remained shut down from throwing for just over two weeks, but the San Diego brass has continued to downplay concern about his elbow issue, noting that some speed bumps were expected coming off the major surgery. While Musgrove is on the shelf, the Padres will turn to Walker Buehler to fill out their rotation.

The Padres placed Canning (Achilles) on the 15-day injured list Wednesday.

Canning is still on the mend from the season-ending Achilles surgery he underwent last summer, but he was cleared to face hitters in a simulated game March 20 and struck out three over a scoreless inning. A clearer timeline for his return will emerge while he builds his workload, though he could return to San Diego's rotation before the end of April.

The Padres selected Buehler's contract from Triple-A El Paso on Wednesday.

Manager Craig Stammen confirmed over the weekend that Buehler had won a spot on San Diego's Opening Day roster, and Wednesday's move makes it official. The 31-year-old righty struggled to the tune of a 4.93 ERA and 1.52 WHIP across 126 regular-season innings last year with Philadelphia and Boston, and he was lit up for seven earned runs over just 3.1 frames during his final start in the Cactus League. If he fails to turn things around quickly, he could be kicked out of the Friars' rotation once Joe Musgrove (elbow) and/or Griffin Canning (Achilles) return from the IL.

The Rangers reassigned Gomber to minor-league camp Wednesday.

The Rangers closed out spring training with the top four members of the rotation all in optimal health, and with Kumar Rocker pitching well enough to beat out Jacob Latz for the fifth and final spot, Gomber never made much of a run at securing a starting role while he attended camp as a non-roster invitee. Gomber will serve as organization pitching depth for the Rangers this season and will likely slot into the rotation at Round Rock.

The Rangers reassigned Quantrill to minor-league camp Wednesday.

The Rangers closed out spring training with the top four members of the rotation all in optimal health, and with Kumar Rocker pitching well enough to beat out Jacob Latz for the fifth and final spot, Quantrill never made much of a run at securing a starting role while he attended camp as a non-roster invitee. He'll serve as organization pitching depth for the Rangers this season and will likely slot into the rotation at Round Rock.

The Blue Jays placed Yesavage (shoulder) on the 15-day injured list Wednesday.

After an unprecedented rise through the Blue Jays' farm system that culminated in a masterful performance throughout Toronto's long postseason run, Yesavage was held out of action during the Grapefruit League for what was initially believed to be workload-management reasons. The Blue Jays then revealed last week that Yesavage was dealing with a right shoulder impingement, which will result in the team stashing him on the IL to begin the season. The injury isn't viewed as a long-term concern for Yesavage, who hasn't been shut down from throwing and was able to pitch in a minor-league game on the back fields of camp Wednesday. He'll likely head out on a rehab assignment shortly after the minor-league season gets underway and could be an option for the Toronto rotation at some point in April. In the meantime, while Yesavage and Shane Bieber (elbow) are both on the shelf, Eric Lauer will serve as Toronto's No. 5 starter.