Nielsen, the Maple Leafs' third-round pick (No. 65) at the 2015 NHL Draft, was the waterboy for the Red Deer Rebels in the Western Hockey League from 2003-05. Phaneuf was a top defenseman for Red Deer at the time.
"It was pretty cool to idolize him, watch what he did best and see him grow as a person," Nielsen told the Toronto Sun during Maple Leafs development camp this week. "I tried to take in as much as I could from him.
"He hasn't called me yet, but the trainer I work out with still keeps in contact with him and texted congratulations. I'd go to Flames games in Calgary when I was younger, where he'd give a puck or whatever. I've not talked to him for a long time, but I'm sure we'll hook up at training camp."