MiLB Notes: Red Sox’ Marcelo Mayer earns Player of the Week honors; internal promotions begin within system

Red Sox top prospect Marcelo Mayer has been named the International League Player of the Week for the week of April 21-27.

Mayer earned the weekly honor for his impressive performance at home against the Syracuse Mets. Appearing in all six games in the series, he went 9-for-20 and batted .450 with three homers, 12 RBI, seven runs, three walks, and four strikeouts.

The 22-year-old’s week was highlighted by his three homers: a 401-foot blast on Tuesday, a 445-foot homer on Wednesday, and a 419-foot homer in the series finale on Sunday.

Mayer got off to a slow start this season, has been on an offensive tear, recording at least one hit in 10 of his last 12 games, and is now slashing .280/.324/.548 with four doubles, seven home runs, 34 RBIs, 17 runs scored, one stolen base, and seven walks over 23 games this season.

His 34 RBI leads all hitters in International League play. The next closest players, Daz Cameron, Rece Hinds, and Otto Kemp, all have 21 RBI.

On the defensive side of the ball, Mayer has been playing three positions for Worcester, logging 135 innings at shortstop. He’s mixed in three starts at both second base and third base. He’s committed just two errors in 75 chances this season.

Mayer made a strong case to make the Red Sox’ Opening Day roster out of camp, having an impressive spring training, playing smooth defense while controlling the strike zone, and hitting .333 with a .983 OPS over 20 Grapefruit League games.

Despite his outstanding spring, Mayer was disappointed not to secure a spot on the Red Sox Opening Day roster.

“Yeah,” Mayer said during an appearance on WEEI’s Jones and Keefe show on Opening Day from Polar Park. “All that stuff isn’t up to me. But as a player and based on performance, I feel like I did earn a spot on that team. With that being said, things didn’t go my way, and now I’m here. and I’m just going to get after it every single day. Keep doing what I’m doing.”

The Red Sox have remained adamant that Mayer and Roman Anthony are remaining in Triple-A to work on becoming more complete players before they’re promoted to the 26-man roster.

“Can either of those guys go to the big leagues, probably right now, and compete and do well? Sure. But it doesn’t always work that way,” WooSox manager Chad Tracy said. “There’s a lot of little nuances that the game [in the majors] will expose that we’re working on. So does that mean they can’t go there tomorrow and play? Of course it doesn’t mean that. Yeah, they can. But while they’re here, we clean up all these things that we can.”

Over the last couple of seasons, Mayer's game has been plagued by health issues. The left-handed hitting prospect has seen his last two seasons cut short due to a shoulder injury and a lower lumbar strain. While healthy, Mayer has proven what kind of player he can be, which highlights part of his future development.

“Number one with Marcelo is his health. We want to see him withstand the ups and downs of the season from a health standpoint,” WooSox hitting coach Doug Clark told MassLive’s Katie Morrison-O’Day. “And that’s not only physically, but mentally. These kids are not 30 years old. They’re very young, and they’re very susceptible to ups and downs and how they deal with them. And that’s where we come into play as coaches…but that’s something that he does well already.”

Mayer is knocking on the door of a big league call-up, but with Trevor Story at shortstop, Kristian Campbell at second base, and Alex Bregman at third base, there isn’t a spot for him to play on an everyday basis.

“He’s a tremendous talent,” Clark said of Mayer. “We can’t wait for him to get what he deserves, and that’s to be a champion up there with Boston.”

MORE MiLB HONORS

Red Sox pitching prospect Trennor O’Donnell has been named the Carolina League Pitcher of the Week for the week of April 21-27.

O’Donnell dazzled for Low-A Salem on Sunday, giving up three hits, striking out seven over five scoreless frames, and earning his first win of the season.

The tall righty retired the final eight batters he faced in his outing, hurling 56 pitches, 40 of them for strikes, with four swings and misses.

The 23-year-old has appeared in four games (two starts) for Salem this season. He’s recorded a 4.20 ERA with 19 strikeouts and nine walks over 15 innings of work.

While on the mound, O’Donnell is an imposing presence, standing at 6-foot-7, offering a four-pitch mix: an 89-91 mph fastball, a 79-81 mph sweeper, an 85-86 mph slider, and an 86-87 mph changeup, according to his SoxProspects scouting report.

He’s also been flirting around with learning a splinker, which is a splitter-sinker hybrid pitch.

Since he was drafted out of Ball State, he’s pitched exclusively down in Low-A, owning a career 4.04 ERA with 90 strikeouts and 30 walks over 78 innings. As the Red Sox begin to promote their prospects as the season rolls on, O’Donnell is a candidate to end up with High-A Greenville in the coming months.

O’Donnell becomes the second member of the 2025 Salem Red Sox to earn Carolina League Pitcher of the Week honors. He joins fellow right-handed pitcher Blake Aita to earn these honors. 

INTERNAL PROMOTIONS

The Red Sox promoted three prospects on Monday: infielder Franklin Arias and left-handed pitching prospect Brandon Clarke to High-A Greenville and left-handed pitcher Hayden Mullins to Double-A Portland, as first reported by Beyond the Monster’s Andrew Parker.

Arias is regarded as the Red Sox' No. 4 prospect in the system, according to Baseball America.

The 19-year-old has been tearing the cover off the ball, slashing .346/.407/.397 with four doubles, nine RBI, 15 runs scored, four stolen bases, six walks, and 12 strikeouts in 19 games while with Low-A Salem.

Arias ranks third in swinging-strike rate (6.1 percent) and sixth in batting average and owns a 128 wRC+, per FanGraphs.

He received recognition as the 2024 Florida Complex League MVP, an FCL All-Star, and the top MLB prospect in the FCL.

Defensively, Arias is considered a better fielder than Mayer, with soft hands and advanced range. Even though he’s currently penciled in as a shortstop in the lower levels of the system, he might be better suited for second base as he elevates through the Sox’ system.

“One of the best defensive shortstops in the 2023 international crop, Arias has added strength and bat speed since signing for $525,000 out of Venezuela,” wrote MiLB.com. “He makes advanced swing decisions for a teenager and won Florida Complex League MVP accolades during his U.S. debut last year, leading the Rookie-level circuit in hitting (.355), on-base percentage (.471), slugging (.584), and OPS (1.055) while stealing 30 bases in 51 games.”

Arias has set lofty goals for himself this season, wanting to finish the season with Triple-A Worcester before his age-19 season comes to a close.

“I definitely want to be the best player I can be. [But] I try to take it day to day and try not to look too far in the future,” Arias told The Boston Globe’s Alex Speier earlier this month. “I feel that’s what helped me get that MVP last year, and I think if I can take that day-to-day approach this year, I can have some similar results.”

The last two teenagers to reach at least Double-A were Anthony (2023) and former Red Sox shortstop Xander Bogaerts (2012).

Baseball America does not currently rank Clarke, but that should change in the coming months. The 22-year-old lefty was selected by the Red Sox in the fifth round (148th) in last summer’s draft out of State College of Florida, Manatee-Sarasota.

The southpaw has been impressive to begin the season, posting a 0.93 ERA with 17 strikeouts and two walks over three starts (9 2/3 innings) for Low-A Salem. He’s had two of his first three outings this season; he’s held opposing hitters scoreless.

Clarke pitched in the Spring Breakout game against the Rays, working two innings and hitting 100 mph on his fastball, generating seven whiffs in his outing. He offers a four-pitch mix that consists of a 96-99 mph fastball, an 87-90 mph slider, an 81-85 mph sweeper, and an 87-89 mph changeup.

"Physicality, velo and stuff, but less refined due to less time on the mound," Red Sox senior director of player development Brian Abraham said to MLB.com. "It was an opportunity to get someone into a system with consistency and routine that would allow his skills to flourish."

With his promotion to High-A Greenville, he will occupy the spot in their rotation that Mullins leaves behind.

The 24-year-old left-hander has gotten off to a strong start, recording a 1.06 over three starts (four appearances) for Greenville.

Boston selected him with the 369th overall pick in the 12th round of the 2022 MLB Draft. He underwent Tommy John surgery after he was drafted and has been healthy since and is pitching his way into a possible promotion to Double-A Portland in the near future.

The lefty’s fastball sits between 91 and 94 mph and tops out at 95 mph. He also mixes in an 81-85 mph sweeping slider and a deceptive 83-85 mph changeup, according to his SoxProspects scouting report. His fastball has a lot of swing-and-miss action; despite that, Mullins just focuses on getting the ball in the zone.

“I haven't really ever worked on trying to develop more swing and miss or trying to get more chase out of any particular pitch,” said Mullins.

“It's always been get it in the zone, and that's what we're preaching here: throw everything through the heart of the zone, but have it move wherever it moves. So yeah, that's been the focus. But never really trying to create a swing and miss. Just let the swing and miss create itself.”

Mullins currently sits as the Sox’ 29th top prospect, according to SoxProspects.

His hot start has him with the Sea Dogs for the first time in his career. If he can show he can handle advanced competition in the minors, he could be a candidate to pitch for Worcester later this season.

A competitive season could benefit Mullins, who is eligible for the Rule 5 draft this winter if he is not protected on the Red Sox 40-man roster. Based on how Craig Breslow operated last summer, he moved a handful of prospects who were Rule 5 eligible in trades in an effort to not lose a player for nothing.

Mullins joins David Sandlin, Yordanny Monegro, Blake Wehunt, and Connelly Early in the Sea Dogs rotation. Early's promotion to the WooSox is inevitable.

Speaking of the WooSox, they added two relievers to their bullpen over the weekend, right-handers Jonathan Brand and Gabriel Jackson.

Brand had posted a 0.00 ERA in four games (4 1/3 innings) for the Sea Dogs before seeing a promotion last weekend. Jackson pitched in three games for the Sea Dogs, tossing 5 1/3 innings without allowing a run. He pitched three innings of relief for the WooSox during their doubleheader on Sunday against Syracuse.