The Dane was impressive on his Champions League debut for United.
"Anders has done well in the sense that he's bided his time," said Ferguson. "He's been patient and understands the situation.
"When we signed him, he knew we were going to sign another keeper. Last January, that was put to him at the time that he would come in next season in a position where he had to challenge for a place.
"He was happy with that and delighted to join United. He showed he's a bloody good keeper and a good thing about the two of them is their use of the ball is terrific.
"You've got a sweeper you can play the ball back to all the time, knowing they're going to deliver accurate passes to the back-four and midfield and be confident about it. I think it's a fabulous asset in the modern game."