Paris Saint-Germain manager Luis Enrique said the "unknowns" of the new Champions League format make it hard to judge his team's opening win over Girona on Wednesday.

PSG secured victory after Girona's goalkeeper Paulo Gazzaniga, who had thwarted numerous efforts from the French champions, made a calamitous error in the final minutes of the match to give the hosts a 1-0 win.

But with seven games to go in what is now called the league phase of the competition, the PSG coach said it might take time to figure out the importance of his team's win.

"Winning a match or any title is difficult, but we don't know the dimension of this competition with this format," Luis Enrique said. "We are going to have to play matches against teams that have easier schedules than ours. How many points are we going to need?

"There are many unknowns that need to be cleared up."

Under the new Champions League format, teams play eight matches against eight different opponents, with the top eight sides in the 36-team league automatically advancing to the last 16, and the next 16 playing a further knockout round.

PSG dominated the game for long stretches, but last year's surprise team in LaLiga kept the game level until the dying minutes, when a Nuno Mendes shot squirted between Gazzaniga's legs.

"I think we were superior, but Girona played us in circles and made us dizzy," Luis Enrique said after the match. "At half-time, we said that if we didn't press, we were going to suffer. We had to win, and it was very difficult."

"It was very difficult. I told [Girona manager] Michel that this was worse than giving birth, with all due respect."

Despite the victory, PSG suffered a setback as striker Marco Asensio limped off just before half-time. Luis Enrique was confident, however, in the strength of his squad.

"He felt a twinge. Marco had started the season well. This is professional football, and we have a very good squad," said the former Barcelona coach.

Despite the defeat, Girona manager Michel praised his team's effort and the performance of his goalkeeper up until the goal.

"Now in the dressing room, people are a little bit down, I told them that we have to be proud of the game we played," Michel told reporters. "PSG subdued us, Gazzaniga made some good saves. There were two or three that could have been goals. We have to recognise that their victory is deserved, but we are proud of the way we work.

"Let's see if we get another chance to come to Paris next year."

PSG will next play Reims away in Ligue 1 on Saturday, while Girona travel for a LaLiga match against Valencia.

Information from Reuters was used in this story.