The French club suffered a 2-0 defeat to Real Sociedad in the first leg of their play-off encounter at the Stade de Gerland on Tuesday, with the Spaniards' away goals making them strong favourites for progression.
However, Gonalons believes Remi Garde's men can stage a comeback at Anoeta in a week's time.
"We are disappointed because we wanted to do well in this first leg at home. We know how important it is not to concede goals; tonight we conceded two," the France international midfielder said.
"So obviously we are not in the best position now before the second leg. We know that we faced a very good Spanish team, they caused us a lot of problems. We can only congratulate them tonight.
"We have already turned things around in some games that were not in our favour. We will go over there with a lot of ambition, and even if tonight we are two goals behind we will try to do our best over there."
Meanwhile, Real Sociedad' Xabi Prieto is also remaining cautious ahead of the second leg in the Basque country.
"The tie is not decided. A bad game could condemn us. The team was calm and there were moments to enjoy. We wanted a rematch after they knocked us out nine years ago," he said.
