Friday’s transfer window deadline came with a predictable flurry of activity, as most clubs across Europe made their last-minute additions or tried to offload excess personnel in a hurry.

Scouts can make their recommendations with the utmost confidence because of modern analytics. But names like Fernando Torres, Renato Sanches, and even Mohamed Salah once upon a time still serve as reminders that not every transfer pans out as well as clubs hoped.

Here are five players who made big-money moves this summer, and they may struggle to live up to their exorbitant price tags:

Andriy Yarmolenko, West Ham

New boss Manuel Pellegrini ushered in a handful of expensive signings this summer, though the most perplexing addition was arguably Ukrainian winger Andriy Yarmolenko from Borussia Dortmund. While Manuel Lanzini’s cruciate ligament injury created an immediate opening for another winger at West Ham, splashing a supposed £17.5 million on a 28-year-old who mustered just six goals over a season in Germany is a debatable move.

Of course, questioning Yarmolenko’s Premier League potential without bringing up his impressive tenure at Dynamo Kyiv would be criminal. He did bag 137 goals in 340 appearances over a decade in Ukraine. But with nothing to show after four substitute appearances at West Ham except for a single booking and four losses, it’s fair to start doubting if Yarmolenko can replicate his eastern European success in England.

Malcom, Barcelona

  • Former club: Bordeaux
  • Fee: €41 million

The former Bordeaux man was set to finalize a deal with Roma, but the Ligue 1 outfit reneged on negotiations at the last minute and flipped Malcom to surprise bidders Barcelona instead. The Blaugrana’s swoop for the Brazilian winger appeared to develop in less than 24 hours, as the club wasn’t even reported to have interest in Malcom until he was on his way to Italy.

Adding to an already puzzling move, Barcelona manager Ernesto Valverde later suggested the Bordeaux star wasn’t a specific transfer request he made, but instead it came from the club’s upper management, according to Mundo Deportivo. It remains to be seen exactly how Valverde will incorporate Malcom into his squad, especially after Ousmane Dembele’s unexpected early-season resurgence.

Radja Nainggolan, Inter Milan

  • Former club: Roma
  • Fee: €38 million

Inter have made a slew of notable signings this summer, including Keita Balde, Sime Vrsaljko, and Stefan de Vrij, though none dominated headlines as much as the €38-million swoop for Radja Nainggolan. The man known in Italy as “Il Ninja” swapped the Giallorossi for the Nerazzurri in June after five seasons with the former, setting up a reunion with Luciano Spalletti.

Nainggolan, though, has been no stranger to controversy. His admitted lifestyle of frequent nights out and chain-smoking cigarettes has landed him in hot water with previous coaches. And while the Belgian midfielder remained a fan favorite, that adoration doesn’t negate the fact that the 30-year-old is still a heavy financial risk for a club with lofty ambitions.

Nainggolan has shown he can handle the toils of Serie A despite his boisterous nightlife – and he even notched himself a goal in his Nerazzurri debut Saturday – but if Inter is intent on finally knocking Juventus off their seven-year throne, the club will need him to perform at a much higher level.

Fabian Ruiz, Napoli

  • Former club: Real Betis
  • Fee: Reported €30 million

Losing both your longtime manager and the backbone of your midfield over one summer would rattle any top-level club. Napoli experienced that feeling and could only watch as Maurizio Sarri and Jorginho packed their bags for Chelsea and the Premier League. Now, Fabian Ruiz, the apparent successor to Jorginho, doesn’t bring the same amount of immediate star power as his new boss Carlo Ancelotti.

Ruiz came up through the ranks at Real Betis, making his senior debut as an 18-year-old in Spain’s second tier in 2014. But Napoli fans hoping he will quickly erase the memory of Jorginho may come away slightly disappointed.

The 22-year-old recruit doesn’t possess the same defensive work rate as the new Chelsea man, as he’s more likely to make his own threatening runs with the ball the other way. Exactly how he’ll fit into Napoli’s style is also still up in the air. Ancelotti has left him on the bench for the first two matches in favor of Marek Hamsik, who at one point this summer looked set for a move to China.

Aleksandr Golovin, Monaco

One of the most sought-after transfer-window targets, Aleksandr Golovin eventually ditched the harsh winters of Moscow for the sunny skies of Monaco, snubbing Chelsea in the process. The fleet-footed Russian midfielder will likely operate in the hole behind the striker, or flex his creative genius on the wing, depending on how manager Leonardo Jardim chooses to deploy his side.

However, Golovin shined with Russia at this summer’s World Cup, and now Monaco has committed an infamous transfer faux pas: Never make big-money signings on the heels of an international tournament. The 22-year-old is clearly comfortable playing on home soil, but his journey out west might be coming a little too soon.