Paris Saint-Germain (PSG) coach Luis Enrique has admitted uncertainty about how long it will take to rebuild his team into a top contender in Europe following a disappointing 2-0 defeat to Arsenal in Tuesday’s Champions League clash.

With the summer departure of star player Kylian Mbappé to Real Madrid, PSG, a team in the midst of transition, experienced their first loss of the season.

Arsenal took control of the game with first-half goals from Kai Havertz and Bukayo Saka, while PSG came close with two efforts hitting the post but ultimately struggled to break down the Premier League team’s defence.

Enrique, who sidelined Ousmane Dembélé due to disciplinary issues, took responsibility for the loss but raised concerns over his squad's lack of determination.

"Today we were far away from the standards you need in this kind of match. Arsenal were much better in terms of pressure and intensity; they won every duel," Luis Enrique told reporters.

"It's impossible to play for a positive result when you don't win any of your duels on the pitch; their defenders anticipated our attackers, and our defenders didn't anticipate their attackers. Arsenal were superior."

Last season, the Spaniard guided PSG to the Champions League semifinals, overcoming his former team, Barcelona, in the quarterfinals, with Mbappé netting twice and Dembélé also scoring to reverse the result in the second leg.

Currently leading Ligue 1 and having secured a win against Girona in their opening Champions League group match, Luis Enrique acknowledged that facing Arsenal presented a much tougher challenge for his team.

"I can't properly evaluate the level of our team; we will have to wait until the end of the season," he said.

"This was our first big rival at a higher level. We knew from the first minute they would press us high, and they did it aggressively, and we couldn't cope with that pressure.

"[Arsenal manager] Mikel [Arteta] has been here for five years; I've been in Paris for one year and two months. I don't know where we are. I have a clear idea where I want us to be, but I don't know how much time I will need."