The two-legged tie between the two Spanish powerhouses was the pick of yesterday`s draw, with current Primera Liga pacesetters Barca having won the cup on a record 24 occasions and Atletico triumphant nine times.

It promises to be a mouth-watering encounter, but Messi does not believe it will be as easy for his side as the last meeting between the clubs in October, which saw Barca score five times in the opening half-hour en route to a 6-1 league win.

That was the second time Barca had put six goals past Atletico in recent times, having also thrashed Javier Aguirre`s men 6-0 at the Vicente Calderon in May 2007, but Messi insists: "They are a difficult opponent and we know that it will not be like the league encounter.

"But the tie is over two games and we have the return match at home."

Barca assistant coach Tito Vilanova added: "Atletico Madrid and Sevilla were, possibly, the strongest teams we could have faced.

"All games are different. They will have more respect for us (following the 6-1 win) but they will also have more desire to show that there is not such a big difference between us as we saw in the league.

"Atletico Madrid have good players and are difficult opponents. We will have to be alert, as we must be with all our opponents," he added on his club`s website.

The two legs of the Copa del Rey ties will be played on January 7 and 14.