Javier Hernandez says the prospect of beating Liverpool gives Saturday's Premier League meeting extra edge.
United host Liverpool in the early kick-off knowing a win would see them leapfrog Manchester City in the table.
"You know in your mind it's Liverpool and it doesn't matter where the teams are in the league, you want to win," Hernandez told BBC Radio Manchester.
"In Mexico we know about the rivalry. Across the world everybody knows about the history of the two teams," he said.
"They have both won a lot of titles and European Cups and everyone knows all about that but when I got here it was different. I learned a little bit more.
"We work just the same as we do for every game. But in the back of your mind, you know it is Liverpool."
The Anfield side are seventh in the league and struggling to regain a place in the Champions League places but they knocked United out of the FA Cup at Anfield a fortnight ago.
It looked like being back-to-back defeats for the reigning champions when they went 3-0 down at Chelsea last weekend, but United recovered to draw 3-3, with Hernandez scoring a dramatic equaliser, his eighth goal of the campaign.
Manchester United go into the game two points behind leaders City, who travel to Aston Villa on Sunday, as the two Manchester sides look like pushing each other all the way in the race for the Premier League.
"We are going to fight until the end of the season for the title," Hernandez said. "Every fan knows that all the players and all the coaching staff want to win the league here.
"This season has been very bad for us with injuries. We have a lot of important players injured but it is a big squad and we are doing our best."