Max Scherzer has been placed on the 15-day injured list with back spasms, the team announced Wednesday.
It will be Scherzer’s second stint on the IL. He was shelved from April 24 to June 10 due to right forearm tendinitis and left ankle inflammation.
The 41-year-old righty has a 10.23 ERA with 14 strikeouts and 11 walks over 22 innings this season.
Fisher will serve as an opener in Wednesday’s game against the Red Sox at Fenway Park, a role he’s filled four times already this season.
Rotation help could be on the way, as Shane Bieber threw a season-high 80 pitches in his fifth rehab start earlier on Wednesday.