Marcelo Mayer sits due to illness on Friday

Story added that he’s feels fine from a physical standpoint after kicking off a minor league rehab assignment over the weekend. The 33-year-old veteran shortstop has missed the entirety of Boston’s remarkable midseason turnaround while recovering from sports hernia surgery. It sounds like he could return later this week after getting a few additional rehab games under his belt. Andruw Monasterio has done a remarkable job handling shortstop for the Red Sox over the last few weeks.

Mayer, out since late June with a stress reaction in his forearm, is 5-for-14 with a homer in three games since joining the River Cats. They might wait a few more days, but the Giants will likely activate him this week and install him as their starting second baseman.

Mayer was viewed as one of Boston’s potential future franchise cornerstones just a few years previously. He simply never found his footing at the highest level despite possessing impressive raw talent and a sweet-looking left-handed swing. The 23-year-old former fourth overall selection from the 2021 draft has struggled to stay healthy at the highest level and the Red Sox ultimately decided to move on, using him as a trade chip to fortify their bullpen. The meteoric rise of Franklin Arias, who has emerged as the club’s potential shortstop of the future, seemingly sealed Mayer’s fate here. It’s a decent move for his long-term future as he’ll get a change of scenery and plenty of opportunities to emerge as a key contributor in San Francisco.

The Red Sox sure are burning a lot of talent here. Miller is quite good and under control for three years after this one, but giving up a long-term regular for a left-handed reliever is quite a loss of value. Mayer is currently on the shelf with an arm injury and might not be much of a factor this year, but he should be the Giants’ second baseman next year and he remains very much an option at short if the club could find a taker for Willy Adames. Miller’s fantasy value disappears with the deal, since he won’t be a candidate for saves in Boston. With the Giants shedding both he and Caleb Kilian, Dylan Smith is probably their favorite for saves at the moment.

Monasterio led off the 10th with his sixth homer of the year. There was certainly no plan for him becoming Boston’s starting shortstop at the beginning of the year, but he’s been quite valuable in hitting .259/.320/.459 in 204 plate appearances. Barring a big trade acquisition, he should continue to play regularly until Trevor Story returns and maybe beyond that.

Cheng goes to make room for Curtis Mead on the active roster. He hit .256/.318/.282 in 44 plate appearances while helping to fill in for Trevor Story and Marcelo Mayer. Andruw Monasterio will serve as Boston’s everyday shortstop for now. Romy Gonzalez is probably the backup, though he hasn’t played the position in two years. Ceddanne Rafaela would probably be the better option, in truth.

Mayer landed on the injured list with a stress reaction in his left forearm. He was allegedly playing through the injury for two months, which may have impacted his performance on the field. It may just be a couple of weeks before Mayer could begin a rehab assignment, but his role in Boston for the remainder of the season remains to be seen. The team has been thriving, and they have multiple options in the infield with Romy Gonzalez back and Anthony Seigler and Tsung-Che Cheng providing value. The Red Sox could opt to keep Mayer in Triple-A to get consistent at-bats until rosters expand in September.

Monasterio came up with the bases loaded against Devin Williams in the ninth and worked a walk even after declining to challenge a called strike on a clear ball to begin the at-bat. That gave the Red Sox their first run before Jarren Duran tied the game with a shallow flyball. Before that, Monasterio had Boston’s only extra-base hit of the game off Zach Thornton. He’s 3-for-5 with a homer and three RBI the last two days, raising his OPS from .629 to .694. The win was Boston’s ninth in a row, with sweeps over the Angels, White Sox and Mets. It’s the first time since 1977 that they’ve gone 9-0 on a road trip.

Monasterio homered off Freddy Peralta in the fourth to start the scoring. That proved to be sufficient for Boston’s pitching staff, but the Red Sox did get some insurance in the form of another two-run homer from Masataka Yoshida in the eighth. Monasterio’s homer off Peralta was his fifth of the year but his first off of a righty; he was hitting just .195/.213/.253 in 89 plate appearances versus righties coming into the day. The triple was the second of his career and first since 2023.

Seigler was replaced by Andruw Monasterio at second base following a home-plate collision with Chicago catcher Kyle Teel while scoring on a wild pitch in the third inning. He came away with a laceration on his right arm and looked to be pretty shaken up after a head-first slide. He’ll undergo evaluation to determine whether he suffered any additional injuries on the play. There should be an update on his status after the contest.