Squishy clutch on 1991 Mazda Miata MX-5

Had a soft squishy clutch so had the slave replaced about 4000 miles ago and now its squishy again. Do you think I now need to replace the master? or the slave again? Hopefully not the full clutch assembly - This '91 has 80K miles. I love this car.

Asked by for the 1991 Mazda Miata MX-5
Have you been loosing any fluid? Any fluid at the top of the clutch pedal inside the car (you need a flashlight and look in from the driver's foot well area).
Engine oil frequently leaks down from the top of the engine and the oil damages the rubber cover on the clutch slave cylinder and clutch slave hose on the passenger side of the gear box bell housing.
If you have fluid loss the same fluid that contaminated one hydraulic component will have contaminated the other component so it may fail in the near future if not replaced.
If you have no problem engaging gears (the clutch hydraulic system is doing its job of breaking the drive between engine and transmission), if the clutch does not slip or chatter it is probably OK.