Ander Herrera has told his Manchester United teammates that they must show the right spirit if they are to advance through to the semi-finals of the FA Cup.

The Red Devils face West Ham United in a quarter-final replay tomorrow night at Upton Park - a venue where the hosts have not been beaten since August 22.

"In the Premier League you show your balance [by being consistent over the season], but in the cup you show your spirit and your desire to win. The FA Cup is a big competition, it's very emotional," the Spanish midfielder told the club's official website.

"If we beat West Ham we'll have the chance to play at Wembley, which is a fantastic stadium. I have a lot of things in mind about being there and we have a big chance to be there, but of course West Ham away is not easy."

United last lifted the FA Cup in 2004 thanks to a 3-0 victory over Millwall.