The defeat saw them fall three points behind new leaders Atletico Madrid in the race for the Liga title, and level on points with Real Madrid in second.
But Martino insists it was just a minor blip.
"I don't think we'll stumble again," he said. "Even though we're second in the league it's in our hands.
"We always talk with the players and certainly after a game as unusual as Saturday's.
"We discussed our mistakes. They get harder to recover as we play more games.
"But whenever there is a loss, the next game in an opportunity to put things right."
Barcelona meet Real Sociedad in the Copa del Rey semi-final first leg on Wednesday, and Martino revealed he had yet to decide who will play.
"I have named all 22 players because of the importance of the match," he added. "And because I still haven't decided who will play.
"It's crucial we keep a clean sheet at home. It's almost as good as a win, certainly with the attack we have."
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