However, speaking to Sky Sports News ahead of Chelsea's visit to Old Trafford this afternoon, the England coach disagreed with Van Gaal's assessment of his side's capabilities.
"I've not seen any evidence of it so far that they're anywhere near Chelsea, and they're going to have to win today if [they're going to win the league] but I'm not having that," he said.
"I look at Chelsea and they're streets ahead of this Manchester United side. I'm really intrigued about how United will approach this game.
"Van Gaal says about his philosophy and how he plays the game, but he will have to adapt that today against this Chelsea team."
United are currently eighth in the Premier League, 10 points adrift of leaders Chelsea.