The 2018 World Cup was such an enthralling experience that the transfer window has been largely forgotten about over the last month or so - let alone the fact it will end three weeks earlier than usual for Premier League clubs this time around.

So, which sides have wisely got their business done early, and who's facing a race against time to get a squad together by the time deadline day arrives? Here's a quick look at what every big six club still has left to do...

The Least - Man City

Signings: Riyad Mahrez

Exits: Angus Gunn, Yaya Toure, Pablo Maffeo, Angelino, Ashley Smith-Brown, Rodney Kongolo, Javairo Dilrosun, Olarenwaju Kayode, Divine Nash, Jacob Davenport, Isaac Buckley-Ricketts (12 players loaned/released)

Contracts expiring in 2019: Eliaquim Mangala, Vincent Kompany, Brahim Diaz, Joe Hart

After masterminding a record-breaking Premier League title win last season and already securing the services of Riyad Mahrez for the coming campaign, Pep Guardiola will be more than happy entering the new season with the squad already at his disposal. After all, he's got at least two options for pretty much every position and Benjamin Mendy, after missing the vast majority of last term, will be like a new signing anyway.

The only real issue for City is finding an alternative to Jorginho, who's ended up following Maurizio Sarri to Chelsea instead. It's not an immediate concern - the Italian was being targeted as the long-term successor to Fernandinho at the base of midfield - but if it can be addressed this summer, City will be keen to bring a player of that profile into the club.

Overall though, the onus is never really on the champions to strengthen and a whole host of deadwood from the reserve ranks has already been ousted this summer. If City can sign a deep-lying midfielder and find new homes for Joe Hart and Eliaquim Mangala, it will be pretty much a perfect summer for the reigning champions.

PL Spending - July 17th

Liverpool

Signings: Naby Keita, Fabinho, Xherdan Shaqiri, Isaac Christie-Davies

Exits: Emre Can, Jon Flanagan (Nine players loaned/released)

Contracts Expiring in 2019: James Milner, Daniel Sturridge, Divock Origi, Alberto Moreno, Lazar Markovic, Ragnar Klavan, Connor Randall

Although there are some signings still in the pipeline, Liverpool have probably been the big six's most clinical executors this summer. The Fabinho deal came out of nowhere, the swoop for Xherdan Shaqiri was wrapped up within a few weeks of the rumours first emerging and Naby Keita's services were secured well over twelve months ago.

On the outward front, there's still some work to be done though. Daniel Sturridge, Divock Origi, Alberto Moreno and Lazar Markovic are now into the final year of their contracts and would all benefit from moves away, but it's more a question of whether they can find clubs who want to take them on, rather than the Reds being obliged to sell. Extra depth certainly won't be a problem for Jurgen Klopp.

In addition to the impending arrival of Alisson from Roma for a world-record goalkeeper fee, Liverpool's pursuit of Nabil Fekir could go right down to the wire and if Lyon don't agree a deal with the Anfield outfit, they'll still have the final three weeks of August to find another suitor from abroad willing to meet their valuation of the France international. That puts the Reds under some pressure, but if Klopp has proved anything from his last two transfer windows, it's that he's fully prepared to be patient and wait for the right player to become available.

[brid playlist="4766" player="12034" title="World Cup 2018"]

Arsenal

Signings: Bernd Leno, Stephan Lichtsteiner, Sokratis, Lucas Torreira, Matteo

Exits: Santi Cazorla, Per Mertesacker, Jack Wilshere (10 player loaned/released)

Contracts Expiring in 2019: Danny Welbeck, Aaron Ramsey, Nacho Monreal, Petr Cech, Stephan Lichtsteiner, Chuba Akpom

With five players already signed in an attempt to almost completely rebuild a backline that was painfully porous away from home last season, the remainder of Arsenal's summer business seems to hinge on who could leave the club before Unai Emery can consider bringing more players in. Perhaps Steven N'Zonzi will end up at the Emirates Stadium before the close of play, but the question of exits seems far more pertinent.

Aaron Ramsey's yet to agree a contract extension beyond next summer, it remains to be seen just how valuable Mesut Ozil is in the eyes of Emery and Petr Cech could well be on his way out following the arrival of Bernd Leno.

In fact, Arsenal could end up with too many players to actually register in their 23-man squad, although the north Londoners will feel there's no great rush with three weeks of the transfer window left to go. Emery will be pretty content with the incomings and outgoings that have already taken place this summer - many of which were even concluded before the World Cup - although if there are some big-name departures, the new Gunners gaffer and Sven Mislintat may well be tempted into getting a late signing or two over the line.

Man United

Signings: Fred, Diego Dalot, Lee Grant

Exits: Michael Carrick, Daley Blind, Joe Riley (1 player loaned/released)

Contracts expiring in 2019: Anthony Martial, Juan Mata, Ander Herrera, Phil Jones, Chris Smalling, Luke Shaw, Matteo Darmian, Antonio Valencia, Ashley Young, Andreas Pereira, James Wilson

The situation on the red side of Manchester isn't so rosy. In theory, United's squad is already bursting at the seams with established talent, but the Red Devils were so far off their noisy neighbours last season it's quite staggering that the only first team addition so far has been midfielder Fred, the  other signings being youngster Diogo Dalot and veteran (presumably third-choice) goalkeeper Lee Grant on a free transfer.

The Brazilian should provide a key point of balance between Paul Pogba and Nemanja Matic in midfield, but the two other departments - the front and backlines - still desperately need addressing. It's not wholly obvious what United's best centre-back partnership truly is, Antonio Valencia and Ashley Young are no spring chickens and for all the options United have on the left of attack - Anthony Martial, Marcus Rashford and Alexis Sanchez - they don't have any convincing ones on the right.

It could well be a case of United needing to generate more funds before they spend big, and there are plenty of players who could be thrown on the scrapheap - Matteo Darmian, Luke Shaw, Juan Mata and Martial all fall into that category as part of a large collection of players whose contracts expire next summer. If that is what's holding up United's business though, there's a great deal to be done before the transfer window slams shut.

Tottenham

Signings: None

Exits: Keanan Bennetts, Anton Walkes

Contracts Expiring in 2019: Toby Alderweireld, Jan Vertonghen, Mousa Dembele, Fernando Llorente, Michel Vorm

Classic Tottenham leaving all their business to the last minute, but the real concern is whether Daniel Levy's old trick of delaying deals as late as possible to get best value will actually work in a transfer window that ends three weeks earlier for the Premier League than the rest of world football.

Tottenham still lack an obvious understudy to Harry Kane and are yet to resolve the futures of Toby Alderweireld, Danny Rose and Mousa Dembele. But the pool of clubs interested in those players seems to be getting smaller and smaller, and Tottenham are just one of three Premier League sides yet to make any signings.

It must be a real bugbear for Mauricio Pochettino, who was insistent upon key changes at the north London club when he signed a new contract at the end of last season. It seems Spurs are once again falling into the same age-old trap and there are no guarantees Levy can pull it off during what is the most unique summer transfer window in Premier League history.

The Most - Chelsea

Signings: Jorginho

Exits: (22 players loaned/released)

Contracts Expiring in 2019: Thibaut Courtois, Olivier Giroud, David Luiz, Pedro, Cesc Fabregas, Gary Cahill, Lucas Piazon, Willy Caballero

Having waited so long to appoint Sarri, Chelsea's transfer window essentially only started a few days ago when they announced the signing of Jorginho. It's certainly a step in the right direction but considering how poor Chelsea were last season, finishing a title defence in fifth place, there's still huge work to be done at Stamford Bridge in practically every department.

Most worryingly, however, is the list of players who could easily leave west London this summer. The futures of Willian, goalkeeper Thibaut Courtois, captain Gary Cahill and talisman Eden Hazard are shrouded in serious doubt and should the whole quartet be sold this summer - which isn't a scenario entirely in the club's control due to various contract situations - Chelsea will be facing a real race to put together a competitive and experienced squad in time for the close of the window.

On top of that, Sarri needs to find a way of actually moulding this squad around his philosophy, which is incredibly far removed from Antonio Conte's in terms of both playing style and formation. It already seems like it will end up being a case of the Italian having to work with what he's been given, rather than bringing in his own recruits. But in any case, Chelsea really don't have long to make up lost ground this summer.