interesting sound coming from clutch
So I've been noticing recently that a soft whirring sound is coming from my clutch sometimes. The sound is only there when I throw the clutch in, and disappears immediately when I release the clutch. Another note, it doesn't seem to happen when the engine's cold, only when It's warm. Would I be right in suspecting a throw out bearing? I can't seem to think of anything else that would cause this, but would like a second opinion. BTW, it's a 2wd, 4 cyl.