Justin Masterson, who was placed on the DL Thursday with right shoulder inflammation, long-tossed Sunday morning for the second time and is improving.
"He's come out of the last two throwing sessions, even though they've been short with 15-20 throws, (well),'' said Farrell. "We're just trying to have him do some really intense flat-ground throwing. We're targeting sometime during the middle of the week to go back on the mound (for a side session). He's responded well to the medication and the limited throws he's made.''
Farrell said Masterson would need to throw two bullpens before the Sox get ready to send him out on a rehab assignment to the minor leagues.
He was unsure how many rehab starts Masterson would need before returning to the big league club.
"We'll go start-to-start with that,'' said Farrell.