They can still make the playoffs without Wheeler. They probably just can't win a series.
Who knows - he could still go Monday. He could be out for the season (given how little is left). Or he could pitch, but not well, due to pain and/or a slight change in grip.
What young arms? Nobody's actually ready to pitch in the big leagues. Even if you weren't still playing for this season, which you are, they probably have more decisions to make about the guys in the major league bullpen - potential non-tenders, trades, re-signings - than anyone in Allentown who might pitch twice in the next three weeks. Those players need to stay in Allentown, they've lost enough development this season already.
Might be worth just throwing Damon Jones out there on Monday though, if they can find a spot for him.
Wonder what ever happened to Victor Arano. Does he even stay on the 40 this off-season?