Messi: Casillas is one of the best goalkeepers in the world

Barcelona forward Lionel Messi has voiced his admiration for Real Madrid skipper Iker Casillas, and admitted that he is surprised to have scored so many goals against him.

The Argentine is widely said to be in direct competition with the Spain goalkeeper for this year's Ballon d'Or after the 31-year-old led both club and country to success.

"I have had a lot of luck being able to score a lot of goals in Clasicos, which are always great games," he told reporters. "I am pleased because Iker is one of the best in the world. He is a great keeper. Sometimes, when games are about to start, I just tell myself to score goals."

Barcelona and Real Madrid drew 2-2 in their most recent clash, although the Catalan outfit tops La Liga with 19 points, which is eight more than the capital club.