Gallen (elbow) threw three innings and 45 pitches in a bridge game at the Diamondbacks' training facility Tuesday, MLB.com reports.
Given the pitch count, Gallen doesn't appear to be far away from returning from the 60-day injured list. He'll still need to push his pitch count up over one or two more rehab outings, but the report indicates that Gallen could be a candidate to rejoin the Arizona rotation during its series with the Royals, which runs from Sept. 7 through 9.