Monasterio is out of the lineup for Sunday's game against the Mariners.
Monasterio will be on the bench for a second straight game while the Red Sox give Anthony Seigler another turn at second base. Boston went with Monasterio at the keystone in each of the three games before that, with the 29-year-old going 2-for-10 with four strikeouts in those contests. Monasterio and Seigler could work in a timeshare at the position while the Red Sox are without all of Trevor Story (sports hernia), Romy Gonzalez (shoulder/hip), Nick Sogard (oblique) and Isiah Kiner-Falefa (forearm).