Defender Patrice Evra said Manchester United would not be treating Saturday's pre-season match against Barcelona as a friendly.
It has been just over two months since the Catalan giants beat Sir Alex Ferguson's side 3-1 in the Champions League final at Wembley, a match dominated by Barcelona.
The Wembley defeat was the second time Evra has lost to Barcelona as a Manchester Untied player, and he said he was determined to avoid a third defeat in Washington DC on Saturday.
"The final is the final. Saturday will be a friendly game," Evra said.
"For Manchester United, there is never a friendly game."
"You have to win every game. You have to respect the shirt when you play, and you have to win."
"I have already lost to them twice and it's very painful."
"At the moment they are the best team in the world, which is difficult for us to accept because that is what we want to be."
United are undefeated so far on their North American tour, with wins over the New England Revolution, Seattle Sounders, Chicago Fire and the MLS All Stars.
Barcelona, meanwhile, were competing in the Audi Cup pre-season tournament, which they won thanks to victories over Brazilian side Internacional and Germany's Bayern Munich.
Pep Guardiola's side now turn their attention to their vanquished Champions League foe, but defender Gerard Pique does not believe there is much separating the sides despite the one-sided nature of their last meeting.
"To be fair, I think that we are on the same level," Pique said.
"It's true that we were lucky to have won the Champions League last year, and I think we had a great game, and we deserved to win."
"But the difference between one team and the other is so small ... I think that we have to give everything we have, try to be as fit as possible to compete well and compete against them and play the game to win."