The inevitable came to pass on Sunday as PSG retained the Ligue 1 title. They beat Monaco – the last club other than PSG to be champions – on Sunday evening at the Parc des Princes thanks to a brilliant hat-trick from Kylian Mbappé, but their crown was secured a few hours earlier thanks to the Toulouse defence, who put on a wonderfully rugged display to hold second-placed Lille to a scoreless draw. PSG have the chance to complete a domestic double when they face Rennes in the Coupe de France final on Saturday. With Neymar, Edinson Cavani and Ángel Di Maria all approaching full fitness, the Breton side are unlikely to spring a surprise.

Neymar and Cavani returned from injury against Monaco, but Mbappé was the star on the night – as he has been this season. His three goals moved him on to 30 in the league in just 27 matches; no Frenchman has scored as many in a single campaign since Jean-Pierre Papin hit 30 for Marseille 29 years ago. Of course, Cavani and Zlatan Ibrahimovic have exceeded that total, but Mbappé has been saddled with more pressure and has been without his regular attacking teammates for much of the season. Neymar has made just 14 appearances in the league and Cavani, who was first hurt at the World Cup, has not been at his physical best for the majority of the season.

After winning the World Cup last summer, Mbappé has clearly established this season that he – and not a more heralded South American – should function as the focus of PSG’s attack. Neymar has been remarkably efficient this season – scoring a goal for every 90 minutes on the pitch – but his fitness has been a concern since he arrived in Paris. On top of that, he seems to operate beyond the normal rules of what is expected from a professional football player – extensive mid-season breaks in other continents included.

The hierarchy at PSG have a lot to consider before next season. Selling Javier Pastore and Yuri Berchiche last summer allowed the club to bring in a handful of players, but they the new arrivals have not really taken the team forward. Juan Bernat has improved as the season has gone on, but the Spaniard is far from the standard needed; he has had his moments going forward, but he is far more of a liability defensively than Berchiche was. In goal, Gianluigi Buffon has brought experience, but his gaffes against Manchester United were especially painful when seen in the light of Alphonse Areola’s development.

Thilo Kehrer and Leandro Paredes were expected to address positions in the team that have become thin due to players ageing (Thiago Silva, Thiago Motta), but neither has truly stepped up. Considering some of the other players who have moved clubs in these positions in recent years in Ligue 1 (Ferland Mendy, Wylan Cyprien, Morgan Sanson), one wonders if, again, PSG’s desire to have global reach has undone their sporting ambitions – especially considering how much young talent French football has produced in recent years.

That wealth of young players clearly extends to PSG’s own youth ranks. Some players – such as Odsonne Édouard and Jean-Kévin Augustin – were not at the standard required, but there are youngsters at the club who may look for new pastures if they are not given opportunities. Jonathan Ikoné and Mike Maignan both left the club to be given chances and they were instrumental in Lille’s 5-1 demolition of PSG a fortnight ago. Moussa Diaby, Christopher Nkunku and Antoine Bernede have all shown impressive flashes for PSG this season, but Bernede has already departed for Red Bull Salzburg.

Lille hammer 'beginners' PSG as they close in on the Champions League Read more

If the QSI project is to succeed, PSG need to give these youngsters a chance to flourish. The team may suffer the odd poor result domestically but promoting young players will keep their stars fit for the Champions League, add depth to the squad and make the club more sustainable in the process. Not every young player will succeed – Colin Dagba and Stanley N’Soki have looked out of their depth at times this season – but even those who do not make it to the very top can be sold to help the club stay within the bounds of Financial Fair Play.

PSG’s obsession with international players over their own academy products hamstrings the club. They have missed opportunities to give youth a chance in the past but now is the time for a more sustainable edict to be put into place.

Ligue 1 talking points

Facebook Twitter Pinterest Marseille players celebrate during their 3-1 win at Guingamp this weekend. Photograph: Sebastien Salom-Gomis/AFP/Getty Images

• It’s scarcely deserved, but somehow Marseille have a shot at playing Champions League football next season. They are five points behind Lyon and are playing uninspiring football, but their run-in is kind and they still have to face Bruno Génésio’s team (a week after Lyon play second-placed Lille). The meeting between Marseille and Lyon at the Vélodrome could prove decisive – as it did last season, when Memphis Depay rescued Génésio and Lyon’s own top-three bid. Fourth-placed St Étienne are also smelling blood; having won four of their last five matches, they have momentum. If Marseille do sneak on to the podium, it would only conceal a dying project and a patchy squad. Whatever happens, change is desperately needed.

• Marseille’s 3-1 victory at Guingamp on Saturday means the hosts were the only side in the bottom three not to win this weekend. Dijon’s dramatic 3-2 victory over Rennes means they have taken seven points from three games, having picked up just one from the last available nine. Meanwhile, Caen, who surprised Monaco with a 1-0 away win last month, repeated the trick on Saturday against Nice at the Allianz Riviera. Goalkeeper Brice Samba produced a superb display – just as he did at Monaco – saving Rémi Walter’s penalty. With Amiens and Monaco both losing this weekend, the bottom three are now just four points behind. Next week’s meeting between Dijon and Caen will be pivotal.

• Reims’ 2-0 defeat to St Étienne brought their European dreams to a halt. They have won just one of their last seven games and are now six points behind the European places. It has been an outstanding campaign for David Guion’s men, but they will have to wait for another chance to emulate Raymond Kopa and the rest of the Reims’ 1960s vintage, who took the club on to the continent. The quality of their recruitment, coaching and squad is indisputable though, so keep your eye on the Stade Auguste-Delaune next season.

Ligue 1 results

Quick guide Ligue 1 results Show Hide Nantes 3-2 Amiens

Toulouse 0-0 Lille

Reims 0-2 St Etienne

PSG 3-1 Monaco

Guingamp 1-3 Marseille

Nice 0-1 Caen

Nimes 2-1 Bordeaux

Strasbourg 1-3 Montpellier

Dijon 3-2 Rennes

Lyon 2-1 Angers

Ligue 1 table