Messi & Mbappe reunited, La Liga's thrilling title race & the return of Napoli: Nine reasons we're buzzing for European football to start again

Stories of internal strife within the Paris Saint-Germain camp have been all too common over the 18 months.

Although the Neymar-Messi-Mbappe trio undoubtedly makes for fantastic viewing, transfer rumours, contract disagreements and behind-the-scenes issues have dominated headlines.

And after the World Cup final, it's hard to imagine things getting easier.

Though Neymar was able to move on from the disappointment of Brazil's quarter-final exit to offer congratulations to Messi for Argentina's victory over France, public communication between the seven-time Ballon d'Or winner and Mbappe has been limited at best.

Instead, rumours of Mbappe leaving for a new club have begun to swirl again, while Messi's request to parade the World Cup trophy at Parc des Princes has reportedly not gone down well.

It could be a turbulent time for PSG in 2023 - and we've got the popcorn out ready to watch it all unfold.

Although much of Barcelona's season has been defined by their group-stage exit from the Champions League, Xavi and his players have quietly pieced together a solid league campaign so far.

They hold a narrow two-point lead over arch rivals Real Madrid at the top of the table, and have only lost once in the league, with that defeat coming at Santiago Bernabeu.

Madrid, then, are still very much in the running, and with Carlo Ancelotti at the helm, cannot be ruled out.

It will likely all come down to the next Clasico, scheduled for March 19. Whoever wins that one will likely be in pole position ahead of the run-in.

With an unbeaten record and an eight-point lead at the top of Serie A, it's hard to see Napoli losing momentum in Italy. But how far can they go in the Champions League?

Their performances in Europe this season have been electric, with Luciano Spalletti's side winning five of six games, including a 6-1 battering of Ajax in Amsterdam.

Although there's quality all over the pitch, breakout winger Khvicha Kvaratskhelia has been the star. Known locally as "Kvaradona", the Georgian has been a joy to watch since arriving in the summer.

Assuming Napoli hold on to the key pieces in their squad during the January transfer window, the sky is the limit for the Partenopei.

Germany's World Cup was one they will want to forget in a hurry.

Embarrassed by Japan and eliminated in the group stage, Hansi Flick's side fell miles short of expectations.

Still, among the negativity, youngster Jamal Musiala shone. One of the standout midfielders at the tournament at just 19, though he still has a long way to go, he is already a key player for both club and country.

He returns to an unstable Bayern Munich camp that has been rocked by injuries to Sadio Mane, Manuel Neuer and Lucas Hernandez, and so they will need Musiala's quality to ensure they both remain top of the Bundesliga table and go deep in the Champions League.

Musiala tends to thrive regardless of the situation, and so we can't wait to see how the ex-Chelsea trainee continues to step up over the next few months.

You may not have been aware of them heading into the tournament, but it's not like Portugal's Goncalo Ramos and Argentina's Enzo Fernandez weren't playing football before the World Cup.

Ramos is in the midst of his best season yet, with nine league goals in 11 matches for Primeira Liga-leading Benfica.

Fernandez, meanwhile, has been pulling the strings from midfield for the Portuguese outfit, and impressed having been given his first taste of Champions League football following his summer arrival from River Plate.

But after standout performances from both in Qatar, the world is going to be watching their club form much more closely.

Both have already been linked with massive money moves away from Estadio da Luz, but it's unlikely that Benfica would let either move on January.

Instead, we can't wait to keep tracking Ramos and Fernandez's progress, and we're excited to see what they can do when the Champions League returns, as a last-16 clash with Club Brugge awaits them.

Things suddenly look a little uneasy for Bayern Munich.

With a lengthy injury list and usual stalwarts such as Leon Goretzka, Joshua Kimmich and Thomas Muller coming off difficult World Cups, Julian Nagelsmann's side are vulnerable, even if they do have a four-point lead at the top of the Bundesliga table.

So, who might catch them? Freiburg, RB Leipzig, Eintracht Frankfurt and Union Berlin are all within seven points of the leaders, with Borussia Dortmund just behind that group.

All four of Bayern's closest contenders should be well rested, with only a handful of their players jetting off to Qatar over the last month.

In-form Leipzig will have to weather the loss of star man Christopher Nkunku to a knee injury, but a late push from Marco Rose's team is still possible.

The odds are slim, but Bayern might just be beatable this year.

While Napoli appear to have Champions League football guaranteed for next season as they aim to now secure a first Scudetto since 1990, the top-four race in Serie A is heating up.

Six teams are competing for three spots, with only four points separating third and seventh place.

Notably, Jose Mourinho's Roma are still in with a shout. Currently seventh, they have decisive fixtures against AC Milan and Napoli coming up, and 'The Special One' will feel that he can sneak his team back to the top table of European football.

That is, if he remains Roma manager - rumours linking Mourinho to the Portugal job are rampant.

It is widely known that Bellingham will leave Borussia Dortmund this summer. The interest in his future destination was palpable before the World Cup, and after a standout series of showings for England, public scrutiny has only increased.

Every day, new rumours emerge on his potential destination. It seemed, for a few weeks ago, that Bellingham was set to sign for Liverpool, largely because of his parents' reported preference for their son to play on Merseyside.

But Real Madrid have always been in the picture, and in early December, PSG got involved, with president Nasser Al-Khelaifi admitting that "everybody" wants to sign the midfielder.

Regardless of where Bellingham ends up, the next few months should bring a fascinating conclusion to one of the most gripping transfer sagas in recent memory.

It's all gone wrong for Sevilla this season.

They were swept aside in the Champions League group stages and tumbled down towards the basement of La Liga.

Manager Julen Lopetegui was swiftly let go, with Jorge Sampaoli brought in to replace him. And while Sampaoli has brought some stability to results, Sevilla are still in the relegation places.

There is hope that Morocco's heroes Youssef En-Nesyri and Yassine Bounou could give the team a lift following their standout showings in Qatar, but it's far from a guarantee that the latter will even remain at the club beyond January.

It's difficult to see Sevilla going down, but just how safe they'll be from the drop heading into the final weeks of the season is uncertain.