Camaroz28lt1383

I was at the track last thursday and have been noticing on my 02 Z28 that when I go out and beat on the car a little that the clutch pedal is sluggish to come back up and it makes it hard to hit the next gear at the track or around town. Not sure if anyone has had this problem before. Its pretty much all stock except 410s. Maybe slave cyl. or master cyl? Just wanna see what everyone thinks before i just go throwing parts at it. Thank you. Paul