Phelan worked with the Leicester City defender when in charge of the Tigers.
He told the Daily Mail: "He wanted to know where he was at, all the time.
"He was interested in the GPS system that tracks distance covered and intensity.
"Harry was one who now and again wanted to get information on players from Manchester United. 'How did so and so deal with that? Why would I need to be in this type of position at this moment?' It's an education when making that jump to the Premier League."