"I would put my hand in the fire as many times as I had to for my team," he told reporters. "I have absolute confidence that we can do it.
"We have an adverse result, it's not good, obviously, but our mentality and our conviction needs to be that we can turn it around. It will be difficult but not impossible.
"We have to play this match as it if was a final. That's what our mentality needs to be from the first minute to the last. I think the fans are confident that we can turn the tie around."
Barcelona are currently 13 points clear at the top of La Liga.