Manchester United boss Louis van Gaal says Chelsea's Jose Mourinho is one of the best coaches in the world.
The Red Devils host the Blues on Sunday knowing that a positive result would boost their chances of breaking into the top four in the English Premier League.
"Chelsea are one of the top teams, as are Manchester City at the moment," van Gaal said on Friday.
"Jose [Mourinho] has worked more than a year with his team and last year didn't win anything.
"You have to build up. They are playing like a team and we have to as well, but to play for 90 minutes.
"I know Jose already has talent because I let him do [manage] Cup matches instead of my other coaches.
"He's a wonderful coach and to see him as a coach winning trophies in other countries is fantastic.
"That you can never imagine that he is a very modest and emotional human being - and I like that. But it's a surprise, no? He's one of the best coaches in the world."
The Dutchman also confirmed midfielder Ander Herrera and winger Angel di Maria will both be fit and available for selection.
"Ander was already fit and, with Di Maria, I said after the game that it [the injury] wasn't so heavy and it's not," said van Gaal.
"It was only the first day that he didn't train so it's no problem.
"I'm sorry to say no other players are back, even if I let Michael Carrick play in London for the Reserves [at West Ham] because you need to play matches when you are injured for five months. He told me it was his first game for the Reserves."
