With Everton close to securing the £50million signing of Richarlison, Watford are ready to receive a healthy profit on their asset.
The 21-year-old Brazilian joined the Hornets for £11.5m last summer and the club are making a staggering profit of close to £40m – a deal too good to refuse.
With the buy-low, sell-high model all clubs look to achieve when they dip into the transfer market, Sportsmail looks at the most profitable transfers in football history from Alisson’s switch to Liverpool to Neymar trading in Barcelona for Paris.
Aymeric Laporte (Athletic Bilbao to Manchester City – £57.2million profit)
Athletic Bilbao have a habit of developing some real gems but even those running the academy for the La Liga club will admit Laporte exceeded expectations.
The French defender joined the Basque club as a 16-year-old before going on to make 222 first-team appearances, scoring 10 goals.
Manchester City boss Pep Guardiola has long been a fan of the centre back and jumped at the chance to activate his £57.2m release clause in January.
Bilbao are experts in profitable transfers and Laporte is one of their finest examples.
Having been in and out the team following his winter arrival, Laporte will want to establish himself as a regular starter this term having got to grips with the physicality of the Premier League.
Alisson (Roma to Liverpool – £57.9m profit)
Francesco Totti said it himself, this was a deal Roma simply could not afford to turn down.
Jurgen Klopp’s Liverpool have long been after a world class goalkeeper and they did not hesitate in making Alisson a world record signing for his position this week.
The Brazilian No 1 managed to keep out Ederson, who was so impressive for Manchester City last season, at the World Cup in Russia and Reds’ fans will believe they have the missing piece needed for a serious title challenge.
Roma signed Alisson from Internacional in 2016 for a modest £7.1m but he quickly established a reputation as one of the game’s finest.
With Simon Mignolet and Loris Karius failing to convince the supporters or the manager, the pressure will be on Alisson to live up to his price tag both domestically and in Europe.
Riyad Mahrez (Leicester City to Manchester City – £59.6m profit)
Le Havre are no strangers to moulding raw talents into world beaters. World Cup winners Paul Pogba and Benjamin Mendy had a spell with the club, as did Dimitri Payet and Mahrez.
But when Leicester City parted with £400,000 for the Algerian in January 2014, the Foxes are unlikely to have foreseen how high his stock would rise.
Mahrez was pivotal in Leicester’s remarkable run to winning the Premier League title and his partnership with striker Jamie Vardy made his one of the must-have players on the market.
It took a couple of transfer windows longer than he had hoped, but having finally secured his move to City, Mahrez will want to show his team-mates and the club that he was worth their £60m investment.
He faces strong competition in wide areas from Leroy Sane and Raheem Sterling but with City battling on four fronts, he is certain to get chances to impress this season.
Cristiano Ronaldo (Manchester United to Real Madrid – £67.8m profit)
In the end the decision came down to boss Sir Alex Ferguson. Keep Ronaldo or allow him a switch to Madrid. In the end the Portuguese was sold for a world record fee at the time of £80m.
He arrived at Old Trafford in 2003 from Sporting Lisbon for £12.2m and he soon transformed into one of the Premier League’s finest both physically and technically.
Madrid’s Galactico policy was in overdrive with Ronaldo and £56m Kaka arriving in the same week but the former has more than paid back the club in his nine-year spell.
Five Ballon d’Or awards, four Champions League titles and two La Liga titles is a return to satisfy even the most critical of Madrid supporters.
A recent £100m switch to Juventus reinforces his value at the age of 33 and he will look to add his sixth European title with the Old Lady in a bid to consolidate his place as the game’s Greatest Of All Time.
Gareth Bale (Tottenham to Real Madrid – £75m profit)
From emerging as a left back at Southampton to scoring one of the Champions League’s greatest ever goals in the final win over Liverpool in May, Bale’s career has rarely showed signs of slowing down.
Once moved into attacking positions under Harry Redknapp at Tottenham following his £10m switch to London, Bale looked a different proposition entirely and soon became the north London club’s focal point and cult hero.
Goals from distance became commonplace and his set-pieces were pulled off with devastating precision – it was inevitable that Madrid would come calling for his services.
Madrid chief Florentino Perez is a huge admirer of Bale and stopped at nothing to bring him in, eventually thrashing out an £85m world record deal with Spurs chairman Daniel Levy.
For all his doubters in the Spanish capital, Bale has scored crucial goals to win major trophies but injury has hampered his progress, as did his relationship with Zinedine Zidane, with the Welshman regularly benched.
But despite suggesting he would consider his future after the win over Liverpool in Kiev, Zidane has gone, Julen Lopetegui is in and Bale has a fresh start. With Ronaldo gone he is ready to take the mantle as the club’s main man.
Ousmane Dembele (Borussia Dortmund to Barcelona – £81m profit)
He may have gone on strike to get there but Dembele made sure he secured his lucrative move to Barcelona.
While Dortmund were incredulous at his behaviour ahead of the switch, the German giants will reflect in retrospect on a move that brought an unbelievable profit.
Dembele is one of the brightest young talents in the game today and the Frenchman was a real coup for Dortmund when he arrived from Rennes in May 2016.
But with the shock departure of Neymar leaving the Catalan club short, there was nobody they wanted more than Dembele to replace him.
Returning to the Nou Camp as a World Cup winner, the 21-year-old will look to kick on under Ernesto Valverde and make a spot alongside Lionel Messi and Luis Suarez his own.
Paul Pogba (Juventus to Manchester United – £89m profit)
Letting Pogba leave for free as a raw, young star before bringing him back as the most expensive player in the world remains a head scratcher for everyone at United.
Under Ferguson, Pogba failed to show the consistency required to earn more game time and with agents advising him, he opted to join Juventus where he enjoyed lots of success.
Nurtured by Antonio Conte and then Massimiliano Allegri, Pogba thrived in a three man midfield and soon became Jose Mourinho’s top transfer target as he looked to rejuvenate Manchester United.
It took a world record fee of £89m to get him but the player had the chance to prove to the club and the fans it was a mistake to let him go.
A stop-start first season back in England left much to be desired but his impressive World Cup for France is a sign that a more mature Pogba will show himself for the new campaign.
Philippe Coutinho (Liverpool to Barcelona – £136.5m profit)
When Brendan Rodgers began recruiting as Liverpool manager, the studious boss saw something many did not in Coutinho.
Picked up cheaply from Inter Milan, the Brazilian playmaker had never been afforded the time to establish himself in a side at the elite level until his move to Anfield.
His skill and flair quickly became apparent and it was only a matter of time before his dream move to Barcelona surfaced.
Viewed as the long-term heir to Andres Iniesta following the Spaniard’s departure at the end of last season, Coutinho was a player Barcelona wanted whatever the costs and it provided Liverpool with ample funds to beef out their squad.
There were fears losing Coutinho in January could be catastrophic for the Reds but they only got better with Sadio Mane, Roberto Firmino and Mo Salah taking on greater responsibility.
A win-win for all involved.
Neymar (Barcelona to Paris Saint-Germain – £149m profit)
The transfer that changed the transfer market. Few felt it was possible for clubs to meet the eye-watering fees stipulated in the contracts of stars like Neymar.
But with a burning desire to step out from Messi’s shadow and PSG looking for a marquee name to announce themselves at the top table, it quickly gathered momentum.
The Parisians met the £198m release clause with little fuss and got their man – all future deals would feel the inflation the Neymar deal caused.
He’s been reported to be unhappy in Paris, a claim he denied. Reported to want to return to Spain, again denied.
He took to the league with ease last season but knows a Champions League title is imperative this season. It was, after all, the whole reason he was brought in.
Kylian Mbappe (AS Monaco to Paris Saint-Germain – £166m profit)
Right now, Mbappe is the man. He stole the show at the World Cup and his permanent transfer to PSG has been confirmed having had a year on loan from Monaco.
The 19-year-old is the shining light of Monaco’s transfer strategy – rose through their youth ranks before becoming the most sought after player on the planet.
The Frenchman is only going to get better and with nobody sure how the market and fees will settle in the years to come, this could prove a bargain for PSG.
His relationship with Neymar has come into question after comments from his mother but with a World Cup winners’ medal round his neck now, Mbappe has every right to take centre stage and help deliver domestic and European titles.