Andre Villas-Boas has slammed United coach Rene Meulensteen's suggestion that Chelsea are too old to win the Premier League.
The Dutchman said that the London club's tempo is not high enough and that Juan Mata, Chelsea's "one major signing", will not be enough to help them to the title this season.
Ahead of his first trip to Old Trafford as Chelsea boss, Villas-Boas has defended his team.
"I find it strange he would say something like this when we have all seen the importance of players like Ryan Giggs, Edwin van der Sar and Paul Scholes to Manchester United," the former Porto said, according to The Sun.
"Only this week Giggs was scoring in the Champions League and being praised by everyone. What's the difference between that and some of the players we have?
"We may have one of the older teams in the league but look at the trophies these players have won."
Chelsea, currently third in the Premier League table, trail both United and Manchester City by two points.