Not buying it. Xavi might have some distress. But Iniesta underperforming against Real (after a godly performance against Chelsea) was only down to Pep's tinkering with the formation. Iniesta looked clueless about what he was supposed to do. He was deployed near the left touchline as some sort of second winger inbetween Adriano and Tello (because Pep obviously didn't trust Tello and Adriano alone defensively on that side against Di Maria) while Xavi was deployed very far high up the pitch infront of Thiago and Busquets who were doing some sort of double-pivot partnership infront of a 3 man backline.
No one was comfortable in such an experimental lineup in such a big game. He played a fullback as a striker, a central midfielder as a winger, expected Busquets to play 2 positions at the same time, Thiago to cover Busquets' ass and also deliver something offensively, Xavi to be a striker and a 20 year old B player to perform in one of the biggest games of the season. Pep wants to be unpredictable and confuse the opponent? He only confused his own players. While Mourinho for the first time showed some balls and played his usual 4-2-3-1 formation that he is playing for 2 years now, Pep shat himself. And the sad thing is: Real didn't even play well. No high pressure game. No chances after chances. Nothing. A scrappy corner goal and a well executed counter attack. Both goals preventable by Valdes alone. They played better when they lost 1-3 at home. If Ronaldo didn't bottle it back then, they would have scored at least 3 goals from open play.
Don't blame the players. Blame Pep. If you play 60 different formations within a season and show no consistency, players won't perform consistently either. FACT.