Alex Bregman Down, Marcelo Mayer Up, Red Sox Still Middling

This is not the company the Red Sox hoped they’d be keeping. When they face off against the Brewers tonight, they’ll be trying to avoid joining the Rockies, White Sox, Pirates, and Rays as the only teams in baseball with three separate losing streaks of at least four games this season. Boston currently sits fourth in the AL East and 2 1/2 games out of the final Wild Card spot. According to our playoff odds, the Red Sox have seen their postseason probability fall by more than half since Opening Day, dropping from 56.2% to 25.3%. Only the Braves, Orioles, and Rangers have had a bigger decline.

Boston’s most recent win also provided its biggest loss of the season thus far. When Alex Bregman signed back in February, there was every reason to believe that the Green Monster would be his best friend. His game is designed around lifting the ball to the pull side, and he’s already bounced five doubles and a single off the wall on the fly, to go with three homers launched over it. But the Monster betrayed Bregman on Friday. In the first game of a would-be doubleheader against the Orioles (the second game was postponed, and Saturday became a doubleheader instead), Bregman scorched a single that short-hopped the wall, but as he chopped his steps to back off an aggressive turn, something looked off.

“I was rounding first base and digging to go to second and I kind of felt my quad grab, so I didn’t continue running to second base for the double,” Bregman said. “I just kind of stopped and came back to the bag so I wouldn’t make it any worse. After I felt it, I knew I needed to come out and see the trainer.” Bregman left the game with right quad tightness, telling reporters that he initially feared that the injury might be more severe, but that he felt more positive after the game and hoped he could avoid an IL trip. “Hopefully, I sleep good and it feels great,” he said. “We’ll just see how it presents and take the next step there, just kind of follow the training staff, their lead. But right now, it’s just quad tightness.”

Bregman didn’t sleep good. Pain from the quad kept him up during the night, and an MRI on Saturday morning revealed a “pretty severe” strain. Bregman compared it to the left quad strain he suffered in 2021. That strain kept him out 69 days, from June 17 to April 25. In case the Red Sox are looking for consolation, Bregman looked like himself upon his return that season, running 115 wRC+ before the injury and a 112 wRC+ (with better exit velocity numbers) after he came back. But that’s cold comfort. With a 160 wRC+ this season, Bregman has been the team’s best player, and he’ll be out for at least two months.

It’s hard to overstate how rough a blow this is for Bregman. His 2.5 WAR ranked 11th among all position players. With a .404 wOBA, he was off to the best start of his entire career at the plate. By playing so well, he was also giving himself a chance to exercise the first opt-out in his three-year contract and get the chance at the long-term deal that he’d wanted all along. That may well be off the table now.

Losing Bregman also put a damper on what should have been a celebration, as the team called up Marcelo Mayer, the second member of its Big Three prospects, to fill in. Mayer arrived at Fenway Park between games on Saturday, driven from Worcester to Boston by a clubhouse attendant. He lost his keys somewhere at the ballpark three weeks earlier and “never cared to look for them until I needed to.” So yeah, Mayer is definitely 22 years old. He started at third base that night, a position he had played professionally just six times before.

Mayer is a consensus top-100 prospect with legitimate power. In the post-spring training update to our Top 100 Prospects list, Eric Longenhagen pegged him at number 30, at the top of the 50 future value tier. When considering Mayer today in light of the call-up, Eric let me know that he’d upgraded Mayer to a 55 – meaning Mayer went from the FV of an everyday player to an above-average regular – and pushed him to 14th on the Board. Eric has sometimes been the low man on Mayer because of his difficulty handling soft stuff at the bottom of the zone. Here’s what he wrote back in February, when he ranked Mayer 57th:

Throughout his entire career, he has performed in spite of these issues, but they continue to terrify me. Marcelo’s front side is so upright throughout his swing that it makes it nearly impossible for him to dip and scoop soft stuff at the bottom of the strike zone and below. He can absolutely button a fastball, but big league pitchers aren’t going to show him many of those if he keeps performing like he has against secondaries. Just how stark is the contrast? Mayer had an 87% contact rate against fastballs last year, and a 57% contact rate against breaking balls.

Before his call-up, Mayer was running a 115 wRC+ at Triple-A Worcester, with a walk rate above 10% and a strikeout rate below 20%. However, a 115 wRC+ in Triple-A doesn’t translate to above-average performance in the majors, and we can also do a pretty simple breakdown.

Mayer was a bit better at laying off breaking and offspeed pitches in Worcester this season, which helped him make more contact, but it’s very clearly still his weakness. He had just a .222 wOBA against offspeed stuff.

Mayer has a 54 wRC+ in his first three games with the Red Sox, going 3-for-12 with a double, no walks, and three strikeouts. So far, 52.9% of the pitches he’s seen have been fastballs or cutters, just a few percentage points below the league average. You have to imagine that rate will tick down some. “I don’t think his issues against soft stuff are so bad that he’s at risk of busting,” Eric told me, “but I do think at some point big league pitchers will force him to improve against them.” The power is real, though. Said Eric, “If my grade ends up being light and it turns out he’s actually a consistent All-Star, it’ll be because of how much power he accesses on contact.”

As for his defense, Mayer is a shortstop by trade, and he has also spent a small amount of time at second. Eric put a 45/50 grade on his defense. He doesn’t have great range or arm strength, but he’s got excellent hands and actions, and that should give him a chance to stick at the position long term. Before Bregman’s injury, shortstop was Boston’s major weak point. Since signing with the Red Sox ahead of the 2022 season, Trevor Story hasn’t been able to stay on the field or perform when he’s on it. He’s played in 52 games this season, already the second most of his tenure with the Red Sox, but as Jay Jaffe documented last week, Story has put up -0.2 WAR, thanks to a 62 wRC+ and ugly defensive metrics. Mayer did play some short on Sunday, as Boston gave Story the day off in the hopes that he could reset himself.

Even before the season started, it was clear that the Red Sox needed a plan for relieving Story of his duties, and Mayer looked to be it. Although he’d never been completely dominant, he’d hit at every stop of the minors, his ascent slowed only by a series of nagging injuries. This season, he was hitting well in Worcester, but not well enough to force the issue. He probably could have used more time, but Bregman’s injury forced the issue for him, and its severity likely means that Mayer will be playing every day whether he’s ready or not. If he can’t keep his head above water, Bregman’s injury could be the defining feature of the Red Sox’ season.

The injury adds another layer of intrigue to a Boston infield that has seen far too much of it in recent months. Rafael Devers would be the obvious candidate to fill in at third base, the position he’s held down for the Red Sox ever since the team called him up in July 2017, but manager Alex Cora has made it clear that that won’t happen. It’s been roughly three weeks since first baseman Triston Casas went down with a ruptured patella tendon, reigniting the firestorm of controversy that started back in February. To recap: The Red Sox were adamant that Devers would stay at third base no matter what, then asked him to move to DH two days after signing Bregman. A hurt Devers refused and went to the media, then backed down and became the best DH in the American League. When Casas got hurt, the Sox asked Devers to learn first base on the fly; he once again refused and went public. They went so far as to bring in owner John Henry to talk Devers down, but publicly at least, there have been no further developments. On Saturday, Alex Speier of the Boston Globe wrote that Devers hadn’t taken grounders in three weeks.

In the meantime, Kristian Campbell has been practicing at first base, though the team says he won’t be ready to play there any time soon. To make matters worse, Campbell has looked lost at the plate. After making the Opening Day roster despite ugly spring training numbers, Campbell started his major league career on a tear and quickly signed an eight-year extension. He charged out of the gate with a 17-game on-base streak and ran a 163 wRC+ through April 29. Since April 30, though, Campbell has a wRC+ of -26, with just eight hits in 19 games. His walk rate has dropped by roughly 14 percentage points, and his strikeout rate has climbed by four. His defense has also graded out very poorly, especially according to DRS, which has him at -8, tied for fourth worst among all players, regardless of position.

In all, the Red Sox have gotten a best-in-baseball 2.8 WAR from their third base position, to go with -0.5 from the other infield spots, third worst in the majors. Bregman was singlehandedly keeping the infield in the middle of the pack, but without him, the dirt is a gaping black hole. Boston has also been very vocal about its intention to keep Masataka Yoshida on the IL until his shoulder is healthy enough that he can throw without any restrictions, despite the fact that he’s ready to hit now, he’s not a good defender, and there’s no space for him in the outfield anyway. In other words, even if the team were willing to let Devers play third for the next couple months – shifting Campbell to first and Mayers to second – it wouldn’t make much of a difference because without Yoshida, it wouldn’t have a better bat to insert into the lineup at DH.

For now, the Red Sox will be depending heavily on Mayer and Campbell, two 22-year-old rookies with all of 210 big league plate appearances between them. Everyone who pays attention to the Red Sox spent the entire offseason wondering when Campbell, Mayer, and of course Roman Anthony would make their way to the bright lights and big expectations of Fenway Park. After waiting impatiently for years, the future has come much more suddenly than anyone would have liked.