Real Madrid star Cristiano Ronaldo admits he could sign for Manchester City - but also return to former club Manchester United. Ronaldo is relishing the chance to play his old team and mentor Sir Alex Ferguson.

But asked if he might one day return to English football and sign for United's neighbours City, Ronaldo told The Sun: "The future? I don't know - only God know the future.

"I'm not going to say it is impossible, because in football the impossible doesn't exist. But I can say it would be very, very, very, very, very, very, very, very, very, very, very, very difficult to play at Manchester City. My heart's in Manchester United, that's why!

"I can't say I'm never going back to Manchester United either - but I can say I'm good here in Madrid and I want to be here."