Paul Pogba has claimed he would "stop playing" if he thought Manchester City could not be caught in the Premier League title race.
The Manchester United midfielder is suspended for Sunday's derby clash thanks to his sending off in a 3-1 win at Arsenal last weekend.
This weekend's fixture takes place with City eight points clear of their local rivals at the top of the table, but Pogba insists the void is not yet too vast to bridge.
"If I don't believe [that United can catch City], I stop playing football now," he told the club's official website. "They need to win because they know that we are behind and we are closing and closing.
"Unfortunately I won't play but I will be there to help the team mentally. I need to be there to boost the team and hopefully it will help.
"Manchester City against Manchester United has always been a big, big derby. One city, two clubs.
"It's going to be a big atmosphere in the stadium and a big game with a big team and big players, so that's the game you want to play. I have complete trust in the team."
And the France international wants United to take a positive mentality into the match.
"We need to [attack]," he added. "To win those games you need to give everything. You need to be there offensively, defensively.
"Kill the game when you have one chance because they have quality as well in front and they can kill the game at any time.
"They are first for good reason because they have been doing great. They keep winning and they didn't lose one game and obviously mentally they are very strong. We need to be as good as they are mentally."