Fulmer will begin the season in the rotation at Triple-A Worcester, Christopher Smith of MassLive.com reports.

Fulmer hasn't been a full-time starting pitcher since 2020 and missed the entire 2024 season following UCL revision surgery. However, he was stretched out during spring training and will represent rotation depth in the minors for the Red Sox.

Moore has been placed on the 7-day injured list at Triple-A Worcester due to left arm soreness, Christopher Smith of MassLive.com reports.

It's not clear at this point how long Moore might be sidelined. The veteran left-hander was in Red Sox camp as a non-roster invitee but failed to make the Opening Day roster, and he won't be an option for the big club for a while.

Slaten struck out one and didn't allow a baserunner in a scoreless ninth inning to earn the save Thursday against the Rangers.

Closer Aroldis Chapman entered for the eighth inning with the game tied 2-2, as the lefty-hitting Corey Seager was batting leadoff, opening up the ninth inning for Slaten after Boston took the lead. The right-hander recorded two saves and 13 holds with a 2.93 ERA, 1.01 WHIP and 58:9 K:BB across 55.1 innings as a rookie last season, and he's one of the Red Sox's top relief arms again in 2025, even if Chapman is expected to be the primary closer early on.

Jackson (0-1) took the loss Thursday against the Red Sox after surrendering three runs on two hits and a walk over one-third of an inning. He struck out one.

The right-hander entered for the top of the ninth inning with the game tied 2-2 and struck out Triston Casas to open the frame. Jackson then allowed a single and a walk before serving up a three-run homer to Wilyer Abreu. Jackson emerged as the apparent favorite for saves late in spring training, and though Thursday wasn't a save situation, his 2025 campaign is off to an inauspicious start. Chris Martin and Robert Garcia are also in the closer mix, and rookie Marc Church could also be involved in high-leverage spots.

McFarland threw two-thirds of an inning with no hits or walks Thursday against the Mariners.

McFarland entered the game in the eighth inning after Jose Leclerc gave up two home runs and blew a one-run lead. McFarland put up a 3.81 ERA and 1.24 WHIP over 56.2 innings last year and tallied 19 holds. He could be a primary setup man for the A's alongside Leclerc, at least until Michel Otanez returns from a shoulder injury and is added to the mix.

Leclerc (0-1) blew the save and took the loss in Thursday's 4-2 loss against Seattle. He allowed three runs on two home runs and a walk while striking out one over one-third of an inning.

Leclerc was protecting a one-run lead in the eighth inning but needed 28 pitches to record just one out. Despite the setback, he may be the A's best setup man until Michel Otanez (shoulder) returns from the injured list.

Jax allowed a run on a home run and a walk while striking out one over two-thirds of an inning Thursday against the Cardinals.

Jax wasn't sharp in his first outing of the season as he was pulled after 21 pitches. Jax will reprise his late inning setup role again this season and should see some save chances when Jhoan Duran is used earlier in the game or unavailable.

Chapman (1-0) allowed one hit and struck out one over a scoreless inning to pick up the win over Texas on Thursday.

Chapman, who was named Boston's primary closer earlier this week, entered a 2-2 game in the eighth inning. It appears the decision to use the closer in the eighth was because the Rangers had the top of the order due up. Chapman worked around a one-out, broken-bat single, throwing seven strikes among his 11 pitches. After the Red Sox took a 5-2 lead in the top of the ninth, Justin Slaten shut the door for Boston.

Sewald earned the save in Thursday's 7-4 extra-inning win over the Royals, striking out one in a perfect 10th inning.

After Kansas City tied the game off Emmanuel Clase in the bottom of the ninth, Sewald successfully preserved a three-run lead in the 10th to earn the save in his first appearance with the Guardians. Sewald, who signed a one-year deal with Cleveland in the offseason, started the 2024 season as the Diamondbacks' closer, though he struggled in the second half before eventually losing the ninth-inning job. While Sewald won't overtake Clase, it looks like the 34-year-old right-hander will be trusted with a high-leverage role.

Hendriks was diagnosed with a compressed nerve in his right elbow and expects to resume throwing early next week, Mac Cerullo of the Boston Herald reports.

Hendriks landed on the injured list Thursday after a tough spring, though the team was optimistic his absence would be brief. The initial diagnosis confirms that outlook, and Hendriks could be back after the 15-day minimum if his recovery goes smoothly.