"Jon Lester was placed on the 15-day disabled list yesterday with a strained latissimus muscle. The Red Sox are apparently hopeful the lefthander will miss no more than two or three starts.

Lester was injured during the fourth inning of his start against the Blue Jays Tuesday night. His examination yesterday included an MRI but the Sox were sparse with details beyond that.

"He will be treated with a period of rest from throwing, followed by progressive strengthening program,'' said a statement attributed to team medical director Dr. Thomas Gill. "There is no specific timeframe for his return at this time. His status will be better defined following the All-Star break.''"