Athletic are enjoying a resurgence under new manager Gaizka Garitano and drew 1-1 at Camp Nou earlier this season.
Williams know his team face a tough test against the defending champions, but says they have players who can hurt the visitors.
“Barça is a very complicated opponent, very difficult. We are aware that they have the best player in the world and other very good ones, but we have more than enough weapons and we have always put them in trouble.
“We have to be very close based on the fact that it will be very difficult to steal the ball from them. We must take advantage of the occasions we believe in, and with pressure and unity we can make them very dangerous.”
Source | Mundo Deportivo
Williams is a player in fine form, his three goals and an assist in January saw him named La Liga’s Player of the Month:
He’ll look to test at Barcelona defence that has managed just one clean sheet in their last six games and will be without JordI Alba due to suspension.