The Giants are pushing Whisenhunt's next start to Monday against the Reds, Alex Pavlovic of NBC Sports Bay Area reports.
Whisenhunt was initially slated to take on the Red Sox on Sunday, but the 25-year-old southpaw will get an extra day's rest, with Matt Wilkinson in the mix to toe the rubber in the series finale at Fenway Park. Whisenhunt took the loss in his last start Tuesday against the Guardians, when he tossed 80 pitches (47 strikes) and allowed seven runs (six earned) on nine hits and two walks while striking out one batter across four frames.