Andres Iniesta says Barcelona are first focused on Wednesday night's Champions League clash with Manchester City.
The Catalan club host City in the Round of 16 second leg after winning the initial bout 2-1 at the Etihad Stadium in February.
On Sunday, Iniesta and his Barca teammates host La Liga rivals Real Madrid in the El Clasico for the chance to go four points clear of their arch enemies but the midfielder says the City clash comes first.
"We feel confident about these two games but we also know we'll be playing against two very difficult opponents," he told reporters.
"Perhaps tomorrow's game is more important. And what better way to prepare for a game like Sunday's than with a win against City? On Thursday we'll start preparing for Sunday.
"Every tiny detail matters in the Champions League, and the only thing we're worried about right now is beating City."
