It's certainly all performance-related, which might lead to your other question of why "saving him" might have come up. I don't have a huge amount of business interaction with Zack, but I know he works very hard. He might think that, if I were a "real" friend, and knowing I have a lot of influence with our boss, I might try to keep him in the junior position we are now creating In lieu of his job. I think he could volunteer to take that position (reporting to me, one level down from where he was), especially because our boss is known as an ####### and many people like a buffer from him. I can't let him vie for that job as we need someone stronger in the position.
oof, yeah, that one is tricky... Why would he be aware of the new position though?If he does go that route, that might be where it'll be impossible to salvage the "work-friendship". You can't afford to have a B-player in that type of role, especially one challenged to perform.
I again would go a direct route, saying that
you need/want somebody young/hungry/driven that can be groomed into your role, when you are ready to leave. The way I always view things is that I want people directly underneath me to eventually replace me. and B-players have no place in a role like that. I have used the bolded in the past when letting somebody "down" more gently. He should get the gist of it, I would think.