Hentges (forearm) threw a scoreless inning while striking out two in Triple-A Sacramento's 6-4 loss to Reno on Friday.
Hentges was placed on the 15-day injured list Aug. 30 (retroactive to Aug. 27) due to a left forearm strain. The southpaw began a rehab assignment with Sacramento on Friday, throwing nine of his 14 pitches for strikes. He's running out of time to return to the big leagues this season, as San Francisco has already been eliminated from postseason contention.