Manchester United boss Sir Alex Ferguson is key to the next move of Real Madrid star Cristiano Ronaldo. The Sun says Ronaldo has vowed he will never join Manchester City while Ferguson is still boss at United.

A source close to Ronaldo, 27, said: "Cristiano has always been close to Alex Ferguson and even now they still talk. Cristiano simply would not risk hurting him by joining Ferguson's immediate rivals."

Ronaldo recently spelt out just what Ferguson meant to him.

He said: "When I arrived at United I was 18 and Sir Alex was like a father to me. He taught me many things.

"I worked with him for six years and he is a great human, a great coach. Sir Alex and Jose Mourinho are the two best coaches in the world."