McClair: Man Utd had to sell unhappy Ronaldo
"Look back at the club's history.
"George Best, Eric Cantona and David Beckham have departed United in some shape or form and the club has continued to thrive, and in certain cases, has gone on to bigger and better things.
"A club as big as United is going to have big players and players move on. That's a fact of football life.
"No one player is irreplaceable. Or to put it another way nobody is bigger than the club.
"Selling Ronaldo to Real Madrid is good business. His comments in the past have intimated that he was not happy.
"There's no point keeping a player in that state of mind as it will eventually start to affect those around him.
"We move on."