True, but given the fact that All-Time greats are almost never seen and have basically unlimited training cap space, they are worth their weight in gold, i am not sure if a new manager in div5 is going to get the most out of him, and that has nothing to do with the managers skill. It is more that given his low div, he can't really afford a top rate trainer that would justify this kind of player.
As a supported of the USA NT team, I would hate to see this kind of player end up as a 26yo 115K player (that could have been achieved with a superstar/MVP player), when he has the potential to become a 200K beast for the NT team
You are a definitely correct about a new manager needing guidance in this situation....but if he doesn't want to sell this would be an excellent opportunity for someone from the NT community to mentor him. He should receive mentoring on how to properly train this guy, and the kind of mentoring that will help him accelerate in the ranks/divisions so that he can promote in conjunction with the players development.
If done right, he would be an excellent candidate for what I call the "Play now, pay later" plan. He will be paying the weekly salary for a player that is based on the start of the seasons ratings, all the while receiving training pops and improvement from the player. I have always made trainees part of my core plan...and its great when you have a player that you pay $40K a week, playing like he's worth $75k a week...that is a huge advantage competitively in league play.