Red Sox pitcher Justin Masterson threw a "pretty intense" bullpen session on Friday, manager John Farrell said on Sunday.
Masterson is moving closer to a return from the shoulder tendinitis that landed him on the 15-day disabled list on May 13.
"He'll have at least one more. We'll probably get a total of three bullpens before we send him out on a rehab assignment," Farrell said, per MLB.com. "He's making strong progress in terms of the intensity of the throws, the volume of the throws."