There are a few spas off of the Broad Street line, not too far away from the stadium complex. Oasis/Ocean is near the Tasker-Morris stop. Esther Snyder Beauty Spa is near the, duh, Snyder stop. If you're driving or taking a car service, there are several other South Philly spas available such as Washington Spa. Search the Philadelphia reviews for South Philly and I'm sure you will find something to your liking.