Wheeler (forearm) threw approximately 15 pitches off a mound Saturday, Todd Zolecki of MLB.com reports.
Wheeler played catch Thursday and was cleared for mound work a few days later. The right-hander is expected to throw a bullpen session Monday or Tuesday and will likely toss another later in the week. If he feels good following his throwing sessions, the Phillies hope that he'll be able to be activated around Sept. 20, when they'll return home following their upcoming road trip.