Barcelona defender Thomas Vermaelen has claimed that his teammates need to be wary of his former club Arsenal in tomorrow night's Champions League last-16 tie at Camp Nou.

The Catalan giants have a 2-0 lead following their victory in the first leg at the Emirates.

"Of course we will be the favourites but I know Arsenal, and I know it's not going to be easy," Vermaelen told the club's official website. "I think they gave us a tough time in London.

"You can never say they are out because they will always come back. The second leg is not going to be easy. They want to play football on the floor, they want to keep the ball on the ground and that's what both teams want. They'd rather not play with long balls because that's not the type of their play.

"They have pace and are physical. They have very quick players on the wing and are very energetic. That's what makes them dangerous."

Arsenal have lost three of their last five games in all competitions.