Arsenal captain William Gallas is backing Eduardo da Costa to prove his value at Emirates stadium.

"We know that everybody is waiting for us everywhere in Europe but it is an exciting challenge because we will have to give the maximum as we are the team to beat," Gallas told his personal website.

"He is a Brazilian striker who plays for Croatia [laughs], but he is Brazilian first.

"He gave his best to settle quickly in The Premier League which is not that easy on the family and language level.

"I think that it is the most difficult thing when you discover a new league and a new culture. When I moved to England my wife and the kids came after three weeks or a month later. When you are on your own you ask yourself questions on your sporting performances.

"In such moments you have to feel mentally strong. Eduardo is not a different person. Everybody has to go through this. I can reassure Arsenal fans that he is a talented striker.

"We will see the Eduardo we know from Croatia in a couple of months."