A number of players from Europe's top clubs could depart in the transfer window this summer, but who would be perfect to replace them? We break down some of the best options available.

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ARSENAL
Central midfield
Thomas Partey/Granit Xhaka >> Amadou Onana, Everton

Arsenal are intent on implementing a major midfield reshuffle this summer, with both Partey and Xhaka set to move on. The £67.5 million ($85.8m) arrival of Chelsea's Kai Havertz should add creativity and goal threat in the final third, with reports that he will take a No. 8 role and essentially replace Xhaka. Then, the potential £100m-plus signing of West Ham's Declan Rice would ensure a stabilising presence deeper in midfield, or as a box-to-box option, in the same vein as Partey.

But the Gunners need someone do both roles and give them extra depth. Their failure to land Brighton's Moises Caicedo has seen the club turn to other options, such as Southampton's Romeo Lavia, but Everton's Onana could be a great addition.

In a struggling Everton team, the 21-year-old has not yet exhibited the constructive aspects of his game to their full extent, but his developmental ceiling is high. At 6-foot-4, his physical presence, aerial dominance, ability to hassle, press, intercept and bring the ball forward make him an intriguing prospect if placed alongside more creative midfielders.

BARCELONA
Defensive midfield
Sergio Busquets >> Martin Zubimendi, Real Sociedad

Replacing one of the most influential midfielders of his generation in a like-for-like role is hard to achieve, so certain tactical tweaks may need to be made. Veteran new arrival Ilkay Gundogan can theoretically assume many of Busquets' jobs, but, aged just 24, Zubimendi has already shown enough to suggest that he can take on the responsibility for years to come.

Operating as a lone pivote in La Real's midfield, where he covers huge areas of ground to enable the attacking midfielders to shine, has proved an ideal learning curve and Zubimendi has embraced the task. He protects the ball well, rarely loses possession and, while he doesn't register the 60+ passes per game of the ex-Barcelona legend, he moves it on with effortless rhythm. The progressiveness in his passing has improved year on year (89% accuracy per 90 minutes) and is combative and consistent in everything he does.

Xavi is a big fan, but whether Barca can find a way to afford his €60m release clause is another thing.

CHELSEA
Goalkeeper
Edouard Mendy >> Mike Maignan, AC Milan

Despite missing nearly half of last season through injury, Maignan has enhanced his reputation as one of the top goalkeepers in Europe and is now France's No. 1.

The most striking aspects of the 27-year-old's skill set are his mental alertness, tremendous athleticism, and spectacular reflexes. On many occasions he will save his team through well-timed, assertive interceptions and, instead of simply booting the ball out of play, can get away from pressure by way of neat footwork, audacious body feints and sky-high self-belief.

His steady feet and vision also allow him to distribute from the back with fine precision. Having already won two league titles in two different countries, he has more than enough experience to rival Kepa for Chelsea's goalkeeping role once Mendy departs for Saudi Arabia.

LIVERPOOL
Forward
Roberto Firmino >> Dominik Szoboszlai, RB Leipzig

While finding a direct replacement for Firmino is near impossible -- the high-scoring No. 8-and-a-half / "false No. 9" hybrid is a rarity -- the Brazilian's positive passing and consistent goal scoring will be missed.

Argentina World Cup winner Alexis Mac Allister was an excellent signing (especially at £35m) from Brighton, but the services of such a tactically adaptable midfielder may be required for a deeper role at Anfield.

Szoboszlai, however, is able to find space further upfield and, whether the 22-year-old cuts infield from the left or picks up the ball in more central areas, he's exceptionally skilled at setting up chances through swift combinations with teammates.

His outstanding set-piece deliveries and powerful shot make him a regular threat on goal -- he has scored 20 in 91 games for Leipzig so far -- and though he has been linked with a move to Newcastle, he would surely flourish under Jurgen Klopp. According to reports, the Hungary international's €60m release clause expires at the end of the month, which leaves little time to manoeuvre.

MAN UNITED
Goalkeeper
David de Gea >> Diogo Costa, FC Porto

Though no transfer comes with 100% guaranteed success, the Portugal international goalkeeper is a pretty safe bet at around €70m. Having progressed through the national youth sides, he has taken every challenge in his stride and just completed his second season as an undisputed first choice for Porto.

Costa already appears the complete goalkeeper; his reflexes are excellent, he moves swiftly in all directions and reads the game expertly -- both in terms of anticipating danger and for rapidly feeding passing lanes by means of feet or hands. Furthermore, the 23-year-old has attracted attention for his penalty saving exploits during the last Champions League campaign (three in a row) and has saved a remarkable 11 in his relatively short career.

Something that will attract United if De Gea departs at the end of his contract is the fact Costa's distribution from the back is also assured. He's able to pinpoint passes to central areas, even with his weaker left foot, and find the runs of his full-backs with craftily measured deliveries. And he can still develop further.

PSG
Forward
Neymar >> Xavi Simons, PSV Eindhoven

With Neymar's future at PSG hanging in the balance, securing the return of Barcelona's La Masia-educated Simons -- who spent three years at the club before leaving for PSV on a free transfer last summer -- seems like a no-brainer.

PSG would only need to spend a reported €6m to bring the 20-year-old back due to a return transfer clause in his contract, a fee that is significantly lower than his actual market value. And, on the back of a sensational season with PSV where he scored 22 goals in 48 games, he has proven he has the skills to impress in Ligue 1 now.

Simons is more of an attacking midfielder than a Neymar-esque forward, yet both float seamlessly between the lines and are -- through flair and technical brilliance -- expert at progressing with the ball and creating imbalance in the opposition through dribbles and one-vs.-ones.

REAL MADRID
Striker
Karim Benzema >> Goncalo Ramos, Benfica

As Madrid's tentative €100m pursuit of Tottenham Hotspur striker Harry Kane seems to be heading nowhere and the perpetual €150m links to PSG's Kylian Mbappe also look set to amount to nothing, one of the most desired centre-forward slots in world football remains open now Benzema has departed for Al Ittihad in Saudi Arabia.

Given the lack of striking options available to the plethora of elite clubs in a similar situation to Real Madrid, it's surprising that the spotlight hasn't shone too brightly on the 21-year-old Portugal international. Ramos' 46 goals in 106 games for Benfica have ensured the club will demand a fee in the region of his €120m release clause, but historically they are willing to trade their best players for the right transfer fee.

Ramos burst onto the global scene at the 2022 World Cup with a hat trick against Switzerland and it's the active, energetic nature of his game that makes him so exiting. Quick, mobile, and with continuous sharp movement off the shoulders of defenders, Ramos averages more than three shots per 90 minutes. While most of his goals originate from close range one-touch finishes, he can also improvise and find practical solutions from further out.

Spain striker Joselu has arrived at Madrid on loan to add depth, but the Spanish giants need more up front and they've found success with a dynamic Portuguese forward before.