Bernardino was called up to serve as the 27th man for Saturday's doubleheader against Tampa Bay.
Bernardino was claimed off waivers from Seattle in mid-April and is already onto his third separate stint on Boston's big-league roster this season. The lefty recorded a 3.38 ERA in 13.1 innings of relief during his previous opportunities this season, though that came with a low 19.0 percent strikeout rate.