if i was a betting man, id put my money on the release bearing, it should run smooth but if unchanged at time of clutch change, it could possibly start to whine when no presure is on the clutch pedal, simple way of checkin is very slowly apply the clutch pedal, and just as presure is comming on the pedal the whine will stop. then you can be sure its the release bearing, unless it gets very noisy it should not pose a major problem, in my opionion of coarse, im not a mechanic so hope that helps a little
