#7 Philippe Coutinho | Barcelona

Even seventh place on this list seems farfetched for how steeply Philippe Coutinho has declined in recent years. Yet, the numbers and the fact that he wasn't always horrible for Barcelona do help his case. The Brazilian signed from Liverpool for a gargantuan £142 million in January 2018 as the Catalans absolutely obliterated all sense of logic and reason while reinvesting the money they received for Neymar.
Coutinho began his Barcelona career decently, recording nine goals and seven assists in 22 matches during the second half of the 2017-18 season. However, the following season spelled doom for the attacker as he registered a meager return of 11 goals from 54 matches. The departure of Andres Iniesta and Ernesto Valverde's decision to deploy Coutinho as a left-winger flopped massively as the Brazilian looked out of sorts every time he took to the pitch.
He finds himself on the sidelines at the moment after suffering a serious long-term injury early on in the 2020-21 season.
#6 Nicolas Pepe | Arsenal

Nicolas Pepe was signed by Arsenal in 2019 for a club-record £72 million. It is fair to say he hasn't justified that fee so far, though there is hope for the future.
Pepe was particularly impressive for the Gunners in the Europa League last season, but has struggled so far in England. In 90 appearances for Arsenal, the Ivorian has 24 goals and 15 assists, which are average numbers at best. Pepe has shown signs of becoming the world-beater he was touted to be when he was in France, but injuries and consistency have often troubled him.
Still only 25, he still has every chance to develop into a world-class footballer. The 2021-22 season could be Pepe's best chance of regaining some consistent form after an improved individual campaign last time out.
#5 Lucas Hernandez | Bayern Munich

Lucas Hernandez remains one of the most talented defenders in European football at the moment. Capable of playing as a left-back and center-back, the Frenchman was crucial to the World Cup-winning France team of 2018.
Hernandez joined Bayern from Atletico Madrid for £72 million a year later, becoming the club's record signing. The 25-year-old has made just 62 appearances since then, scoring once and recording five assists. Hernandez has certainly not lived up to the money the Bavarians spent on him, but played an important role in their treble-winning 2019-20 campaign.
The Frenchman's trophy cabinet from his time with Bayern and the fact that he is still only 25 are what place him higher than many others on this list.
#4 Paul Pogba | Manchester United

Paul Pogba's time at Manchester United seems to be heading to an end every summer, but he's still there somehow.
The Frenchman returned for a club-record £89 million from Juventus in 2016 as a champion midfielder with the world at his feet. But Pogba has struggled to scale those peaks again and his consistency has been a constant source of worry for the Red Devils.
Yet there are days - like the recent win over Leeds or the 2018 comeback against Manchester City at the Etihad - where Pogba is unchallenged as the best player on the pitch. Much of the midfielder's time at United has seen him forced to do everything in midfield with little support. The arrival of Bruno Fernandes at Old Trafford has changed that, with Pogba looking more at home at the base of midfield and orchestrating some scintillating moves for Ole Gunnar Solskjaer's side.
Pogba has 38 goals and 46 assists in 207 appearances for United, which is not bad at all given the variety of systems he's had to adapt to. But he only has a League Cup and Europa League to show for his efforts. Perhaps this could be the season where he adds to his trophy cabinet?