Barcelona forward Lionel Messi has insisted that his side have to win against Real Madrid at Camp Nou in the Copa del Rey on Tuesday.

The Blaugrana have the advantage of an away goal in their semi-final tie, having drawn the first leg 1-1 with the defending Spanish champions at the Santiago Bernabeu last month.

"We have to be at our best against Real Madrid because otherwise we won't get through the tie," he told Barca TV.

"In front of our own fans we don't have any other option than to go for a win against Real Madrid; we can't start thinking that a goalless draw would see us through."

Messi has scored 38 goals in 25 La Liga appearances so far this season.