In a match that means so much more to the people of Spain than just your everyday UEFA Champions League , this could be one of the most pivotal ties in the history of European football.
Not only are Barcelona  trailing Atletico Madrid  in La Liga, there is a chance for the impressive, "other," club from Madrid to put the Catalans out of European Cup contention and send changing of the guard chills down the spine's of many a Barcelona and even Real Madrid fan.
The home side have had the better results against their visitors with three wins and three draws against them in their last six meetings, but if Atletico come out attacking and pressing Barcelona early they could turn the match in their favor.
Barcelona are great at pressing the ball as well, but are not great at being pressed and if Atletico can get on the ball and cause the Blaugrana midfield to struggle in possession then there is a good chance that Diego Costa and former Barca forward David Villa can run in behind the home side's defense.
Javier Manquillo remains the only Atletico miss due to injury while Raul Garcia is suspended and Emiliano Insua could be left on the bench because he is a card away from suspension.
The home side will be missing Victor Valdes whom has been ruled out for the next six to seven months with a torn ACL leaving Pinto as a potential weak point in goal for the side. Carlos Puyol, Pedro Rodriguez and Martin Montoya are also all doubts for the match.
Barca XI: Pinto: Alves, Mascherano, Pique, Alba; Xavi, Busquets, Iniesta; Sanchez, Messi, Neymar.
Atletico XI: Courtois: Juanfran, Miranda, Godin, Luis; Koke, Gabi, Suarez, Turan; Costa, Villa.