What the European giants still have to do in the transfer window

The biggest clubs in Europe only have a few more weeks to finish their business. Some of them need to shed weight to appease UEFA's financial watchdog, while others continue to search for the piece that could take them over the top.

Here's what each European juggernaut has to do before the summer transfer window slams shut.

England

Liverpool

The Reds have already completed four signings totaling more than £150 million this summer. With Naby Keita and Fabinho in midfield, Xherdan Shaqiri available off the bench, and Alisson keeping clean sheets, there are few holes left to fill in Liverpool's squad.

The only remaining question is depth. Liverpool would struggle in the event Roberto Firmino, Andy Robertson, or Virgil van Dijk fall injured. Neither Daniel Sturridge nor Dominic Solanke is capable of leading the line by himself, and there's little confidence Joe Gomez and Joel Matip can shore up the defense when called upon.

A move for Christian Pulisic may prove too costly this summer, but another defender and all-purpose forward would do tidy jobs in relief.

Manchester City

After missing out on Jorginho, the reigning Premier League champions are on the lookout for Fernandinho's long-term successor. Manager Pep Guardiola has asked the Brazilian to play in several positions, including defense, but the lack of a natural backup is glaring. Ilkay Gundogan, who has played in that role before, is better suited as a box-to-box midfielder.

Fernandinho also has a tendency to snap, and missed several league matches over the past two seasons due to suspension. If it's City's objective to win on multiple fronts, they'll need another option.

Guardiola has reportedly kept an eye on Borussia Dortmund pivot Julian Weigl for some time, having watched the German midfielder from up close during his tenure at Bayern Munich. The 22-year-old, who's thrived in a deep-lying role at the Westfalenstadion, can break up play and redistribute possession just as well as Fernandinho.

Manchester United

Jose Mourinho has used plenty of stopgaps at the back. It's time for a more permanent solution.

A combination of Chris Smalling, Eric Bailly, Phil Jones, and Victor Lindelof is no longer sufficient for a team of United's growing aspirations. Aside from Bailly, there are significant questions about the quality of Mourinho's center-backs.

An experienced defender like Toby Alderweireld would give the backline a more sophisticated look.

With the Belgian entering his final year at Tottenham, a bargain is there to be had. He's a much cheaper option than Harry Maguire, whom Leicester City appear to value at £70 million. Alderweireld is also comfortable in a back three or four, having played in both systems at club and international level.

That kind of additional depth wins titles, which should be a priority as Mourinho prepares for his third season on United's bench.

Spain

Atletico Madrid

Atletico currently have a squad of 19 outfield players, which is fairly small for a club of their size. It's a nod to their frugal business approach, but not even the most efficient outfits can challenge on multiple fronts with so few numbers. And Atletico continue to sanction departures, allowing Sime Vrsaljko to join Inter on loan while exploring the sale of Kevin Gameiro.

AC Milan's Nikola Kalinic and Chelsea's Olivier Giroud are said to be under consideration, but that's not enough.

Diego Simeone's defensive options remain relatively thin - center-back Lucas Hernandez is often played out of position - and the workload in midfield continues to be shared by a small group of players.

Simeone had just enough bodies last season to win the Europa League, but it's becoming increasingly difficult for Atletico to contend in three competitions.

Barcelona

Barcelona have already reinforced each department, with center-back Clement Lenglet, midfielder Arthur, and winger Malcom arriving in July. Manager Ernesto Valverde, however, is still concerned about the losses of Paulinho and Andres Iniesta. Andre Gomes' future is also undecided.

"We want players who fit our style and we need players in the middle to generate play," he told reporters.

It's not that Philippe Coutinho, Ivan Rakitic, and Sergio Busquets aren't good enough. The midfield is just so important that Barcelona can't afford to ride the same players.

The most convenient solution lies within. Most supporters would like to see more graduates from La Masia, and if not that, Barcelona have the option of reintegrating Rafinha, fresh off a six-month loan spell at Inter.

Real Madrid

Everyone is waiting to see how Real Madrid will react to the departure of Cristiano Ronaldo. They are well overdue to make a Galactico signing - the last of which was Gareth Bale in 2014 - and there's no time like the present.

Eden Hazard is the obvious replacement as a dynamic left winger who can take on players just as Ronaldo did in his first years at the Bernabeu. The other option is Robert Lewandowski, who, according to his agent, wants to leave Bayern.

Club president Florentino Perez may not feel too much pressure - he has a mandate until 2021 - but signing either Hazard or Lewandowski would reinvigorate an insatiable fan base.

Germany

Bayern Munich

Bayern have to decide what to do with Lewandowski before dipping into the market. If he were to leave, Bayern would have little time to identify a like-for-like replacement.

No one in the current squad has Lewandowski's qualities - the closest facsimile is a misfiring Thomas Muller - and there are few affordable options on the market right now. Giroud could come in and do a similar job, though not at the same level as the Polish international.

It's possible Lewandowski is hoping for a better contract - he still has three more years left on his current terms - but the opportunity to play for Madrid is stronger than ever. He has spoken in the past about his admiration for Los Blancos, and without Ronaldo, they are placed perfectly to make a push for the former Lech Poznan striker.

Italy

Juventus

Juventus could easily be crowned kings of the summer transfer market. In addition to Ronaldo, the Bianconeri improved the midfield and defense with the signings of Emre Can, Leonardo Bonucci, and Joao Cancelo.

They've built a team to win now and managed to shed Gonzalo Higuain's enormous wages in the process. Another midfielder would be nice, but the future of Miralem Pjanic is of greater importance. With the likes of Manchester City and Chelsea circling overhead, Juventus needs to work quickly to sign the 28-year-old to a new contract.

Financial Fair Play could become a problem if Juventus continue spending, so it's unlikely they'll make another big splash in the summer market.

France

Paris Saint-Germain

The same can be said for PSG, whose commitment to FFP is under question. They must now do whatever they can to satisfy UEFA.

There's a suspicion the club used its Qatari links to secure lucrative sponsorships with the Gulf nation and thus circumvent FFP. The fact UEFA is reviewing an investigation into PSG's finances is evidence of that mistrust.

It's unclear whether PSG have to sell any big names by the end of the window, but Edinson Cavani, Goncalo Guedes, Thomas Meunier, and Alphonse Areola continue to draw interest. Selling some combination of those players would help PSG counterbalance the more than €400 million spent on Neymar and Kylian Mbappe last year.

(Photos courtesy: Getty Images)