Fiorentina coach Vincenzo Italiano was left concerned after their 3-2 win against Club Brugge.
Suffering a red card, Fiorentina won the first-leg of their Europa Conference League semifinal.
Italiano said: “We regret conceding twice.
“We didn't allow ourselves to win with a wider margin. I am happy with Nzola's goal. It was clear from the start that he had a good attitude, but we must do more in the next match.
“In the end, we tried to put all our attacking players on the pitch and we reaped the rewards. When you have this quality and physicality up front, every opponent struggles. However, I repeat that we should have scored more goals. We had many chances, and we could have scored more goals, but the lads' attitude in the last period has been impressive."
Italiano also said: "Quarta and Ranieri didn't feel the danger. They know they must work well on preventive marking in these situations. Considering the match's trend, I think they lowered the guard, but it's impossible not to believe that this ball would not cause trouble for us. If we had scored the third goal, the game would have finished differently.
“I imagine that, if we have the same attitude of those 10 seconds in the second leg, it won't end well. We must be focused until the end because anything can happen in these matches.
“We could have scored more goals tonight and I am convinced we'll have chances in the next match. As I said before the game, maximum commitment and discipline are needed."