As it stands, the Catalan outfit are second in the table, four points behind leaders Atletico Madrid with just three games remaining.
"We played almost on fire. Not because the game was bad, it was good, but the goal near the end of the first half affected us and more so with 2-0," Iniesta told Sport.
"This team, if they win or play well, plays football. When it doesn't, things get complicated. After this victory we can hope for the title a little longer but it's true that with every game there's less time until the end and it's increasingly difficult.
"But we know that we can't fail. If our rivals don't fail we will congratulate them."
Barca boss Gerardo Martino is widely expected to leave the Camp Nou this summer.