Manchester United boss Sir Alex Ferguson is looking forward to facing Chelsea's Andre Villas-Boas on Sunday.
Ferguson has also been impressed with the manner in which Villas-Boas has adapted to his new surroundings, having been recruited from Porto in the summer at the tender age of 33.
"The new coach has started very well," he said.
"For a young man who has come to Chelsea, it is a great challenge.
"It is a hard challenge at his age but when you go to a new club, you hope you get an immediate response. He has got that.
"They are a team with great experience and they will always be a challenge to us."
