Sticking clutch pedal
 

Whenever I put my car into reverse, the clutch pedal sticks in the "depressed" position which forces me to release it with a quick pull using my toes. The pedal only sticks when I go to reverse. Slave cylinder, clutch, pressure plate fork, IMS changed out several months ago, system bled with a power bleeder and the car brakes fine. I have a new master cylinder standing by in case that is part of the problem. Any thoughts.

99 base w/5 speed and 168K miles

It makes no sense that this happens only in reverse.

None whatsoever, unless (and probably not even if) you are pushing the clutch in harder when you are in reverse.

Does the jam feel "mechanical" in nature?

Do these cars have an "over travel" or "return assist" type spring associated with pedal return? Even then the gear selection would not matter at all.