Scott Brown was controversially sent off for the hosts at Celtic Park, and Lusting admits that his dismissal did have an impact on the rest of the game.
"Our defence was good but we didn't attack as well as we would have liked," Lustig told the press. "Barcelona didn't create that many chances and before they scored their goal we had the two best chances, so we are a bit disappointed. Of course, it was hard to play with ten men against Barcelona but we did well.
"After they scored we had to come out a bit more and that's why they created so many chances late on. We need to go for three points against Ajax in the next game and take at least four points from the two games against them."
Celtic face Ajax in back-to-back fixtures in the competition.