Rafael Leao struck as Milan won Wednesday night's Champions League tie 1-0.
Conceicao said afterwards: “It was a positive result, we still have a lot of work to be done though.
“We knew Girona are dangerous on the ball, our pressing was not brilliant, but we still didn’t allow them much in the first half. Once we stepped up the tempo and made more vertical passes, we created chances to score several goals in the first half.
“After the break, I think we had more fear of conceding an equaliser than we did the desire to score a second. This is one of the things we are here to improve.”
He also said: “We didn’t concede a goal, but must be much more solid and compact as a team. There are moments when we don’t have the ball and everyone has to think the same way, that’s what makes a team in my view.
“It is the first time we kept a clean sheet, but it has to become a habit, as these are the foundations you build success on. Conceding zero goals is the only way to guarantee points!
“The team is working on what I want, I realise that it is not easy, I try to feel the pulse of the side and I saw they were suffering a little, so I moved to five at the back. At this moment, with this atmosphere and situation, the result was too important.”