With a sealed bearing, this all takes place inside the bearing and unless you've opened it up wouldn't be visible, so I doubt that's what you're referring to.
But I assume I'd feel it? So just a change of bearings, rather than a full headset replacement.
I recently thought I'd brinnelled a cartridge headset, but it was just over-tightened. Once I'd taken it out to check which cartridge I needed to buy and put it back, it was fine. I hadn't done 50k on it, however.
But I assume I'd feel it? So just a change of bearings, rather than a full headset replacement.