The defender told The Sun: "Sir Alex said I had looked after myself, had played well and could go on for at least another couple of years. He thinks it is possible for me to do what Ryan Giggs has.
"And when you hear that from the best manager of all time it makes you believe in yourself.
"Sir Alex leaving did make me think: 'Is this the end of an era, is it time for me to go too?'
"There was a lot of emotion around when he told us and I didn't believe it at first.
"But this club will go on and keep challenging for all the major trophies and I want to be part of it."