The Boston Red Sox open up a three-game series against the Seattle Mariners at T-Mobile Park this weekend. For the opener, Marcelo Mayer is out of the lineup. Chris Cotillo of MassLive reports Mayer is battling an illness.
Gasper DH Rafaela CF Abreu RF Contreras 1B Duran LF Kiner-Falefa SS Durbin 3B Narvaez C Monasterio 2B
Boston will be without their starting shortstop for at least the series opener against Seattle. The Mariners are pitching both Bryce Miller and Luis Castillo for this game, both right-handers. So matchups aren’t a reason that the left-handed Mayer is out of the lineup.
Cotillo had reported the day before that a Red Sox player was traveling separately from the team. While there is no clear link between that and Mayer’s absence from the lineup, it is hard not to connect them.
Left-hander Ranger Suarez takes the mound for the Red Sox, with first pitch set for 10:10 pm ET.
UPDATE: Marcelo Mayer was a late addition to the lineup. He’ll bat seventh and play shortstop, per Cotillo. Isiah Kiner-Falefa has been taken out of the lineup.
Gasper DH, Rafaela CF, Abreu RF, Contreras 1B, Duran LF, Durbin 3B, Mayer SS, Narváez C, Monasterio 2B
Red Sox Manager Chad Tracy Gives Update on Marcelo Mayer
With Marcelo Mayer out of the lineup, the Red Sox will start Isiah Kiner-Falefa at shortstop. Andruw Monasterio starts at second base.
There’s no indication yet if Mayer could be available off the bench. If not, then they just have utilityman Nate Eaton left for infield coverage in the case of an injury.
Red Sox interim manager Chad Tracy clarified there is no injury situation going on regarding Marcelo Mayer.
“Just a day,” Tracy told MassLive’s Chris Cotillo. “Keep trying to pop some people in there to get at-bats and give guys a breather.”
It’s been a tough 2026 season for Mayer. He began the season as the Red Sox’s second baseman. After Trevor Story’s core surgery, he’s played at shortstop since.
On the season, he is hitting just .216 with three homers and a .588 OPS. His 61 wRC+ is the sixth-lowest among MLB hitters with at least 200 plate appearances. Mayer had a particularly rough homestand, going 2-for-15 at the plate, as the Red Sox lost four of six.
“Like the rest of the group, having ups and downs,” Tracy said. “There’s periods where you feel like this is getting a lot better and then some stretches of at-bats where you feel like it’s not as good and then it goes again. We’ve just got to keep pushing.”
Marcelo Mayer’s 2026 Outlook
Marcelo Mayer was selected fourth overall by the Boston Red Sox in the 2021 MLB Draft. While he arrived in Boston with much fanfare, his career has gotten off to a slow start. He’s played in 108 games, holding a .221/.280/.343 slash and a 22.7% strikeout rate.
The underlying metrics haven’t been kind to Mayer this season either. He’s struggling to square up the baseball, with a hard-hit rate of 35.8% and a barrel rate of 6.0%. Both marks rank in the bottom 28 percent of MLB hitters. His exit velocity is an astonishingly low 86.1 MPH.
Unsurprisingly, the expected metrics are in line with Mayer’s struggles. He carries a .199 xBA, .291 xSLG, and a .260 xwOBA.
The Red Sox are in a weird situation with Mayer. They’re so far behind in the postseason race that they’re already being discussed as sellers. In that situation, it makes more sense to let Mayer continue to get reps vs. MLB pitchers.
Another decision the Red Sox will have to consider is top prospect Franklin Arias’ viability for 2027. Arias is hitting .307 with 13 homers and a 141 wRC+ with Double-A Portland. If he’s a candidate for a roster spot next season, they could get a look at him toward the end of the season.
Boston Red Sox Announce Marcelo Mayer Change Ahead of Mariners Game