The Substitute Program is being replaced by the Tee Time app.  The tee time app has two parts:  'Tee Times' and 'Ready To Tee'.  They are both found in the 'Play Golf' menu.

Tee Times: If you are looking for a substitute in a league or you're looking for a partner to play on any given day, enter your tee time and everyone will be able to see your opportunity. You will also be able to see anyone that posted their availability in 'Ready to Tee'

Ready to Tee: If you have availability on a certain day or time or are looking to play at a certain course, enter your preferences in the 'Ready to Tee' page.  You will see any matching Tee Times.  Check back often as new tee times will be added regularly during peak season.