Bailey threw a bullpen session off a mound prior to Friday's game against the Blue Jays. He threw 35-40 pitches, working exclusively with his fastball and cutter.
"I don't think he has a health issue to deal with any longer," said manager Bobby Valentine. "He now just has a conditioning, a pitch buildup and a competition challenge ahead of him."
Next up in Bailey's progression will be another bullpen session on Sunday morning at Fenway Park. Valentine expects the reliever to throw 15 pitches of batting practice on Wednesday in Arlington, Texas, during a three-game series with the Rangers.
Fellow injured reliever Rich Hill is also progressing from a left elbow strain. The left-hander is throwing from flat ground. Valentine said Hill came out of a long-toss session on Friday "pain free." Hill has been on the DL since June 10.