There's a well-known saying in France: "The absentees are always wrong."

Neymar missed Paris Saint-Germain's crucial 3-0 win at rivals Marseille in Ligue 1 on Sunday through injury, and considering that it was one of PSG's best performances of the season -- and in Le Classique, no less -- the Brazilian was one of the big losers on the night.

In what was one of the biggest games of the season for the defending champions, Christophe Galtier's side were balanced, compact, efficient. They played with cohesion and a proper team spirit. And the 3-5-2 formation, which got the most out of Lionel Messi and Kylian Mbappe in tandem up front, worked perfectly against the Marseille high line. Together they produced a masterclass, each reaching a career milestone as well: Mbappe notched his 200th goal for PSG, tying the club's record set by Edinson Cavani, and Messi celebrated his 700th goal at club level.

Had Marseille won the game, they would have moved to within two points of PSG at the top of Ligue 1; instead, the gap at the summit has widened to eight points.

We will never know how the game would have gone had Neymar played alongside his two superstar teammates, but the collective expression without the No. 10 on the pitch was the best we've seen this season, and against a good team with an aggressive press and a thoughtful plan.

In all the tough games PSG played this season with their fabled "MNM" trio, against teams with a press and a plan, the front three exposed their limitations. In a 1-1 draw at Benfica in the Champions League, PSG struggled, losing the xG battle against their Portuguese opponents. Against Stade de Reims at the Parc des Princes in Ligue 1, the front three was a burden rather than a boost: the away side had 17 shots and should have won, with the game finishing 1-1. Against Lille at home, PSG made heavy work of things and needed two very late goals for a miraculous 4-3 victory.

If it's true that the defeats suffered by Paris so far this season have come when at least one member of the trio was missing -- no Messi or Neymar at Lens, no Mbappe at Stade Rennais, no Mbappe or Messi at AS Monaco, and just Mbappe for the final 30 minutes against Bayern Munich -- it is also clear that in terms of balance and solidity, the 3-5-2 formation with only two of the "MNM" up front is better against pressing sides. That's the way forward in games of importance, and the Messi/Mbappe duo showed the way against Marseille.

Against lesser teams that play a low block and don't press much, the technical ability of the stars and their capacity to play in tight spaces will always be needed. Against more challenging sides like Marseille, Monaco, Bayern or Benfica, it's no longer enough. The lack of defending and running without the ball from the front three is too much to carry.

Whether PSG line up in a 3-4-1-2, a 4-3-1-2, or a 4-4-2 formation -- all of them previously tried by manager Galtier -- none is really suited for a top game. The French champions are too exposed and too unbalanced.

So ... are PSG better without Neymar? For the big games, there is a feeling in Paris that the "MNM" shouldn't start together because they don't always play well together. Mbappe has to play, of course, and Messi's profile is arguably a better fit for Mbappe than Neymar. However, Neymar has been a steady contributor, with 13 goals and 11 assists in 20 Ligue 1 matches to go with two goals and two assists in six Champions League games.

While Neymar perhaps no longer has the acceleration to go past players like he used to, and his game has not evolved much despite him getting older and slower, he still boasts an incredible technical gift. Yet in some of the big games -- like against Bayern, at Monaco or Benfica -- he has been disappointing.

Equally, his attitude on the pitch has been questioned -- especially at Monaco, where he was seen verbally abusing teammates Hugo Ekitike and Vitinha. He has also been criticised for his off-the-field behavior, including his very late birthday party three days before the game against Marseille, and his trip to a poker club and to McDonald's the day after the Bayern loss. It was noticeable that Vitinha had his best game of the season on Sunday in Marseille, when Neymar was not there.

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At this stage, Neymar is unlikely to be fit for the second leg against Bayern, which makes this a little easier for Galtier. The Brazilian damaged the ligaments in his right ankle against Lille 10 days ago and won't be ready, certainly to start, for the trip to Germany next week.

The manager will likely use the 3-5-2 formation again, with Mbappe and Messi up front together, with every hope of turning the tie around after Bayern won 1-0 in Paris. After that, Neymar will be back, and this conundrum and debate around what is best for this team can begin again.