As Europe's most prestigious clubs fly back to the Old World from preseason tours of all corners of the globe, it's the surest sign yet that the return of club football is just around the corner. As ever, the summer transfer window has seen teams splash stacks of cash, so ESPN FC enlisted Nick Miller to break down some of the new arrivals who are preparing for their debut campaigns in a new league.

- When does the transfer window close?
- Premier League fixtures 2019-20 in full
- When does the 2019-20 La Liga season start?

Premier League

It's always a fun, if slightly pointless exercise to look for weaknesses in Manchester City's side. At the end of last season, the best you could probably come up with is "Fernandinho's getting on a bit," so naturally City promptly fixed that weakness with probably the best option available. Rodri arrived from Atletico Madrid for a hefty €70 million fee, but if the 23-year-old stays and excels for as long as Fernandinho did, then it will look like a shrewd purchase.

At the other end of the spending scale, Tottenham have very much kept their hands in their pockets for the past 18 months, but went big when they eventually did splash out. In theory Tanguy Ndombele is exactly what Spurs need, combining the best qualities of Mousa Dembele and Moussa Sissoko to give them many more options in central midfield. Not all theories work out, but for a team cautious about their business as Spurs are, Ndombele looks like as close to a guarantee as you can get.

It is slightly baffling that, at the time of writing, Arsenal appear to have little interest in buying a central defender who can help them this season. Still, newcomers further up the pitch look quite exciting, with the apparent imminent arrival of Nicolas Pepe and the signing-on loan of Dani Ceballos from Real Madrid. The latter can play in a couple of different roles in midfield, including No. 10: could he displace the already semi-marginalised Mesut Ozil even more this term?

The good news for Chelsea is that Christian Pulisic is used to dealing with expectation. The U.S. men's national team's leading man from an early age, Pulisic will now need to take that experience from the international stage to the Premier League, not only being the only genuinely new face in the Chelsea squad but now carrying the added pressure of having to replace Eden Hazard. With a rookie manager in Frank Lampard having to deal with limited resources, he really needs everything at his disposal to function properly. There's more emphasis on this signing than most.

La Liga

The saga of Eden Hazard's move to Real Madrid was one of the longest running in recent history. The question now is: with that epic brought to a merciful conclusion this summer, will he make the sort of impact to justify the time spent getting him there? Hazard's talent verges on the genius, but regular Chelsea watchers will tell you that he can have long spells of anonymity, even whole seasons when he's below par. Will he get away with that at the most demanding club in the world?

It's an indication of where the transfer market is that Atletico Madrid paying €126m for Joao Felix was of course remarkable, but didn't exactly cause colossal shockwaves. Quite apart from seeing how he deals with the pressure of that fee, it will be fascinating to see how he adapts to Atletico, or maybe more accurately if and how Atletico change their style to reflect their new recruit.

It was only a year ago that Nabil Fekir was a point of obsession on Merseyside, a €60m move to Liverpool agreed only for it to break down over concerns about his knee. Now, after a season in which the playmaker made 29 league appearances with no major injury concerns, Real Betis may have got themselves a bargain, paying a third of that price for Fekir, where he could line up alongside Giovani Lo Celso (assuming he doesn't depart for Tottenham), Sergio Canales and William Carvalho. What a midfield that could be.

Serie A

The continent's most ambitious clubs formed a not-so-orderly queue to pick off the best from Ajax's extraordinary young side this summer, and Juventus snagged maybe the very best, Matthijs de Ligt. Even at just 19, he seems so mature that he'll be able to deal with the pressure and expectation, but we'll only find that out for sure as years ahead pass. De Ligt has been signed at a point where he won't have much time to learn from Giorgio Chiellini and Leonardo Bonucci, almost replacing them straight away.

Perhaps the wider point about Juve's new arrivals this summer is how they will knit together with a new regime, Maurizio Sarri's appointment representing a shift in emphasis from simply winning to doing so in a certain style. It won't be easy, and another challenge could be dealing with Adrien Rabiot, a man who comes with a tricky reputation from his time at Paris Saint-Germain.

The appointment of Antonio Conte and the signing of the grizzled warhorse Diego Godin are two definite signals that this will be a different Inter this season. But how different? How much can these two men of iron will do to turn around a club notorious for incompetence and bad decisions at every turn?

Bundesliga

Another season, another Bayern Munich procession to the Bundesliga title? Perhaps. This is a Bayern in flux, with a head coach who had a variable first season and who have lost their two most experienced players in Arjen Robben and Franck Ribery. There has been a concerted effort to make the squad younger this summer, and the headline arrival has been Lucas Hernandez from Atletico Madrid, for a whopping €80m. Will the revolution of youth prove successful?

Of course, Bayern's biggest challengers will be Borussia Dortmund, but all of their major recruits have been from within the Bundesliga. Snapping at the heels of both will be RB Leipzig, who finished third last term but now have Julian Nagelsmann at the helm and have made a clutch of interesting signings. Chief among those is Ademola Lookman, who curiously didn't get much of a chance at Everton but clearly impressed those in Leipzig enough for them to pay north of €25m for him this summer. This isn't the most eye-catching deal, but if Nagelsmann and Leipzig can get the best from Lookman's talent then it could be among the shrewdest.

Also arriving in Leipzig is Christopher Nkunku, who could probably count himself as among the unluckiest players in Europe in the past couple of years, given that he came through at PSG at just the time they ramped up their spending to recruit the world's best and shiniest attackers. You can't really blame anyone for not dislodging Neymar, Edinson Cavani and Kylian Mbappe, so hopefully a new start will give him more opportunities.

Ligue 1

Perhaps the days of lavish and glamorous expenditure at PSG are over. At the time of writing, it seems that there will be no global superstar arriving, instead the sort of signings that a club with money but also sense would make. Like defender Abdou Diallo, for example, who cost around €30m from Borussia Dortmund, and is an interesting addition for a couple of reasons. Firstly, how often will Diallo play this season will presumably depend on how frequently Thiago Silva and Marquinhos are available. Also, does this arrival mean PSG have moved on from Presnel Kimpembe?

Perhaps even more remarkable than PSG making a shrewd signing is them making a free one. Ander Herrera's arrival from Manchester United probably doesn't signal a huge shift in approach, but does suggest they recognise the value of a functional player who will do a job when it is asked of him. Much like he was at United, Herrera will probably turn out to be a man who gives you 7/10 every week, and even teams like PSG need that.

Joachim Andersen was linked with a number of Europe's biggest clubs over the past few months, so it was interesting to see him rock up at Lyon. Of course this season will see the annual question of whether anyone will challenge PSG domestically, but if Andersen fits in then they will at the least be solid enough to allow their silkier attacking talents to flourish.