Gerardo Martino is reportedly keen to bolster his defensive options as he begins his maiden season in charge at Camp Nou and is believed to be tracking the Brazil international.

Luiz is currently away with the national side as they prepare for a friendly fixture with Switzerland in Basel.

But the 26-year-old is not answering questions on his club career, preferring to focus instead on Wednesday's game at St Jakob-Park.

"I will only talk about the national team because this is all I can think about when I come here, that's how I think," Luiz is quoted as saying by Globo Esporte. 

"It was like this in Brazil during the Confederations Cup, and it will be like this here.

"You (the media) can try everything, but you won't get anything from me."

International team-mate and Barcelona full-back Daniel Alves is keen for Luiz to join him in Spain.

"I would be happy if David Luiz would come to Barcelona. I always want the best for my friends and advise them to join Barca if they get the chance," Alves told El Mundo Deportivo.

"He's not just a friend, but he has a lot of quality, too. The problem is not whether he would like to come here, but that you have to take him away from (Chelsea manager Jose) Mourinho and that will not be easy."