After meeting the evergreen Welshman at a coaching course recently, McDermott believes the 39-year-old will be the next United player to conquer the dugout.
He said: "I met him recently at Burton. He was doing his pro licence and he has got all the ingredients to be a top manager.
"I was really impressed, he came up to me and shook my hand. He is humble and quiet.
"I asked him how many medals he had won.
"He was very modest and just said 12. I asked what he did with them all and he said they were in museums. He was a really polite man."