Gray (hamstring) threw a live batting practice session Friday, Tim Crowley of MLB.com reports.
Gray got up and down three times during the session in what was an encouraging development for the Red Sox's rotation. Interim manager Chad Tracy was pleased with how Gray looked during the live session and will consult with others to determine the right-hander's next steps. Gray landed on the 15-day injured list following an abbreviated start April 20 and is eligible to return Wednesday.