There's a great article on SI.com written by Jake Fischer about Doc Rivers seeing something in one of his young Orlando point guards, Tyronn Lue. Doc told him when he was done playing to give him a call. And a mentoring relationship began:
Lue ended up calling Rivers after his 11-year playing career came to a close in 2009. When Lue was a player, Rivers noted his impeccable attention to detail and a yearning to be a part of the coaches’ scouting reports—preparation most players didn’t concern themselves with. Rivers had no idea where to put Lue on his Boston Celtics staff, but he convinced team president Danny Ainge to take a chance on the veteran point guard most commonly known for being on the wrong side of Allen Iverson’s legendary step-over.
What began as somewhat of an internship blossomed into an apprenticeship. Lue sat right behind Rivers during games, a row back from the Celtics’ bench. As television cameras panned to the sidelines during dead ball stoppages, Rivers would constantly be captured leaning backward and whispering to Lue. “I like his brain,” Rivers says. “Every time I drew up an ATO [after timeout] or anything, he would write it down. If it was something in practice we were experimenting, he loved coming in and wanted to know why. What did you see? Why did you run that? What do you think about doing this and this and that?”
When Doc went to the Clippers, he took Lue with him -- there was more to teach. Also from the same article:
“What I wanted him to understand was the workload,” Rivers says. “As hard as players think coaches work, when they get on the other side, they’re always surprised at the workload, the time and the fact that it never goes away and it’s never off your mind. He accepted it, he did it and he knew, from that point on, ‘This is what I want to do.’”
Lue passed Rivers’s test with flying colors. His work in the film room ultimately resulted in Rivers amending his defensive philosophy to be more congruent with the Clippers’ roster than that of the Celtics. “We had more athletic bigs with Blake [Griffin] and D.J. [DeAndre Jordan]. We could switch more things, our bigs could show and get back,” Rivers says. “Ty saw those things in film, brought ‘em up, we talked about ‘em and implemented a lot of them. He was great.”
And now that Lue has secured his first head coaching job in the NBA and has his team in the Finals, he never stops learning or listening to his mentor. Again, from the same article:
“He’ll text me at times, 'What do you see? How would you score against this action?'” Rivers says. “I’ll draw it up on a napkin at a restaurant and take a picture of it and send it.”