I would ask them why they think they deserve one. And if the answer is, because they have been doing doing such a good job for such a long time ... well, I thin

I would ask them why they think they deserve one. And if the answer is, because they have been doing doing such a good job for such a long time ... well, I think you can guess what my answer would be. On the other hand, if they point out occasions where they stepped out of their comfort zone and succeeded, there might be a promotion on the horizon already and I would discuss with them what's still missing for it to happen.