Manchester United's match against Manchester City in the Premier League on Thursday is "the game of the season" and will play a decisive role in both teams' chances of finishing in the top four, midfielder Ander Herrera has said.
United, who are fifth in the table, trail fourth-placed City by a point and Herrera believes whichever team win the derby will be in pole position to book a spot for next season's Champions League.
"It's going to be the game of the season," Herrera told the club's website. "I don't know the 'winner takes all' expression but it's going to be a massive game.
"If one of us wins it, we are not going to lose a lot of games or make mistakes after that. It will be key.
"We are in a very good moment, on a very good run... and we have to show it on Thursday."
United can also qualify for the Champions League by winning the Europa League. They play Spanish side Celta Vigo in the semi-finals next month.
"We also have the Europa League, which is a competition that makes me very excited... Hopefully we can fight for that title as well, but I know Celta Vigo are very good. They are a very difficult team," Herrera said.
United lost the league fixture at Old Trafford against City earlier in the season.