I don't find it incredible at all that Ryan is still performing at the top level," Kanchelskis told the official site.
"Ryan has always been a great professional who has looked after himself properly. If you are professional in your life and concentrate your efforts in training and matches then you can go on and on.
"I only finished last season. I didn't want to drop down the divisions in Russia so I retired at the top level. I think Ryan will do the same. But it won't be yet.
"If I can play to 38, why can't he? Maybe he will play for another four or five years yet. At the moment I don't see any reason why not.
"I see a lot of Premier League football and watch United a lot. Ryan is still fast and clever. He is still definitely good enough for that level."