The Spain international admitted that the club's hopes of retaining their La Liga title are now all but over but is adamant that they can beat the Blues on Tuesday night
The Catalans had been hoping to close to within a point of Los Blancos at the top of the Liga standings but they came out on the wrong side of a 2-1 scoreline at Camp Nou, with Cristiano Ronaldo firing home the winner on 73 minutes, just moments after Alexis Sanchez had cancelled out Sami Khedira's early opener.
As a result, Barca now trail their great rivals by seven points with just four rounds of the season remaining, and Iniesta conceded that the title race is now effectively over.
“It hurts our soul to not be able to prolong the Liga battle a little more, but we have to accept it,” the Spain international is quoted as saying by his club's official website.
“The Liga title has practically slipped away. The difference in points is large and there are few [points] left.
"We knew that it would be difficult, especially knowing that they depend on themselves - but we gave it a go.
“Our only option was to win and they played with that in mind. With a draw, when it looked as though we were fighting for the win, their quick reply slowed us down.”
Iniesta, though, is in no doubt that Barca can put their Clasico disappointment behind just as quickly and overturn their 1-0 first-leg deficit in their massive Champions League clash with Chelsea in Catalunya.
"We have to be prepared and eager for this Tuesday," the World Cup winner said. "We have to focus on the next competition. A lot is at stake and we cannot falter.
“It’s a completely different game against Chelsea. What we’re concerned about is getting to the final in Munich and the wellbeing of the team.”
Barca's meeting with the Blues at Camp Nou kicks off at 20.45CET.