Mbappe left PSG in the summer to join Real Madrid, marking the end of the Galacticos era.
The French team has long dominated their domestic league, but even having a number of top-class talents in their team has not brought them success in Europe.
This was partly because Messi, Neymar and Mbappé were not always available to play together and it didn't work out as often as hoped.
The club now hopes that a change of identity will bring them the success in Europe that has so far eluded them.
That change was to focus on youth, and in the season opener against Le Havre they started three teenagers – Ibrahim Mbaye, 16, Warren Zaire-Emery, 18, and Yoram Zague, 18 – and only two players over 25.
In the league, it is 22-year-old Bradley Barcola who has taken a big step forward in Mbappe's absence. The striker has scored 10 goals in 12 games and is at the top of the scorers list.
However, he has yet to carry that form into the Champions League, having failed to score in his four European games this season.
“Barcola is under a lot of pressure,” said European football expert Mina Rzouki.
“We always focus on all their stars. How important was it to have someone who could achieve these goals under pressure?”
“Is it a good thing that they refrained from doing that? It was necessary because of what happened in the locker room, but maybe they need a balance.”
Mbappe is undoubtedly a major goal loss for PSG, having scored 256 of them in 308 appearances in all competitions during his six years at the club.
French and Arsenal legend Thierry Henry said earlier this season that PSG had lost some of its “magic” without Mbappe but now had more stability.
“I think they’re a team,” Henry told CBS Sports Golazo. “They are a little more stable – fewer counters. But they still lost Mbappe.”
“It's very difficult. For example in a game like this.” [the 1-1 draw with PSV last month]Kylian can make it 2-1 or score a winning goal towards the end – a moment of magic. He can turn it around.
“They've lost a little magic, but the team looks a little healthier in terms of balance.”
