Former Manchester United manager Sir Alex Ferguson famously dubbed the January transfer window "silly season". It's proverbially a time for panic buys and back-peddling; an admission that you didn't know what you were doing in the summer.
And while that's a belief held by a number of managers, it hasn't stopped many of them spending big down the years. Some of these players turned out to be inspired business, while others stank the place out. Let's take a trip down Memory Lane...
10. Juan Mata: Chelsea to Manchester United (£37.1m, 2014)
An under-pressure David Moyes, midway through his debut (and only) campaign as Man United gaffer, was thrilled to sign a layer of Mata's calibre from rivals Chelsea, in 2014. The Spanish playmaker was seen as too much of a luxury for then-Blues boss Jose Mourinho, and was ushered to away to Old Trafford.
The move never really worked out for Moyes or Mata, as United continued to stagnate over the succeeding years. Mata collected a Europa League, an FA Cup and a League Cup during seven-and-a-half years at United, but never recaptured the form he'd shown during happier times at Stamford Bridge.
9. Bruno Guimaraes: Lyon to Newcastle (£40m, 2022)
After new Saudi Arabian owners arrived in late 2021, Newcastle fans were relishing an unprecedented spending spree at St. James' Park. That January didn't disappoint, as Kieran Trippier and Chris Wood quickly arrived before the biggest signing of the lot; robust midfield playmaker Bruno Guimaraes from Lyon.
The Brazilian was considered one of the best young players on the continent and he's lived up to that billing, pulling strings in the Magpies midfield as they've rapidly become one of the best sides in the Premier League. An absolute bargain.
8. Fernando Torres: Liverpool to Chelsea (£50m, 2011)
Chelsea fans couldn't believe their luck when their club signed Fernando Torres from Liverpool in January 2011. The Spanish striker had forged a reputation as one of the deadliest marksmen in European football.
Yet it was Reds who had the last laugh, as their prized asset fell well short of expectations at Stamford Bridge – the result of injury issues and a loss of confidence that was tough to watch at times.
There was one magical goal against Barcelona in 2012, but little else in the way of quality. It has gone down as one of the worst signings in football history.
7. Luis Diaz: Porto to Liverpool (£52m, 2022)
With Tottenham reportedly closing in on Porto winger Luis Diaz, Jürgen Klopp decided he had to pounce. The Colombian was swiftly signed in a 2022 deal few had seen coming.
Klopp's decisiveness has since been proven right, as Diaz's mesmerising dribbling skills and ability to score from any angle have made Liverpool a nightmare to defend against. A lengthy injury lay off this season coincided with a dramatic loss of form for the Reds, proving his immense worth to the club.
6. Bruno Fernandes: Sporting Lisbon to Manchester United (£54m, 2020)
Ole Gunnar Solskjaer's job was hanging by a thread when the club opted to sign Sporting captain Bruno Fernandes in January 2020. The attacking midfielder had developed a free-scoring reputation in his native land and United were desperate for goals.
It's turned out to be a masterstroke, as Bruno has developed into one of the best creators in the Premier League. His coolness from the penalty spot, and eye for an audacious pass, have become crucial to the way United play, and give Erik ten Hag's side an unpredictability few sides can deal with.
5. Pierre-Emerick Aubameyang: Borussia Dortmund to Arsenal (£55m, 2018)
Gabon captain Aubameyang arrived in the Premier League to much fanfare in the 2018 winter window. He got off to a fantastic start at Arsenal, too, scoring ten goals in his first 12 starts. He would go on to captain the side to glory in the 2020 FA Cup, scoring in the final victory over Chelsea.
While the striker scored 68 goals in 128 games for the Gunners, things ultimately turned sour, as a public falling out with manager Mikel Arteta resulted in him being shipped off (for free) to Barcelona. He later returned to England with Chelsea.
4. Christian Pulisic: Borussia Dortmund to Chelsea (£56m, 2019)
Winger Christian Pulisic became Chelsea’s then-second-most expensive signing of all time when arriving from the Bundesliga in 2019, before being sent back on loan to Dortmund for the remainder of the season.
The USA captain has shown his obvious talent in flashes in the years since, though has failed to convince successive managers that he has what it takes to be a regular in the Blues side. He still has time to turn it around.
3. Aymeric Laporte: Athletic Bilbao to Man City (£57m, 2018)
Pep Guardiola's Man City chose to dig deep to bring Laporte from Athletic Bilbao in the same window as the next player on this list. The left-footed centre-back has been sensational since moving to England, helping the Citizens to four Premier League titles, one FA Cup and four Carabao Cups.
Guardiola famously likes to shuffle his defence, but whether paired with Ruben Dias, John Stones or someone else, Laporte always seems to be at the heart of his backline. Still just 28, you wouldn't bet against him winning many more gongs in future.
2. Virgil van Dijk: Southampton to Liverpool (£74m, 2018)
Eyebrows were raised when Liverpool manager Klopp sanctioned a £74m deal to make Virgil van Dijk the world's then-most expensive defender in January 2018. Yet critics were swiftly silenced, as Van Dijk scored the winner in the Merseyside derby on his debut before inspiring the Reds to that season's Champions League final defeat against Real Madrid.
At Anfield, the Dutchman has developed into one of the world's finest centre-backs, and has played a crucial role in Liverpool's subsequent trophy haul, winning the Premier League, Champions League, FA Cup, League Cup, UEFA Super Cup and FIFA Club World Cup over five glittering years. Money well spent.
1. Mykhaylo Mudryk: Shakhtar Donetsk to Chelsea (£88m, 2023)
After purchasing Chelsea from Roman Abramovich in the summer of 2022, new Blues owner, Todd Boehly, hasn't been shy to get his chequebook out. After forking out for a raft of summer signings, the American business tycoon was determined to pip rivals Arsenal to prime target Mudryk in January.
Some baulked at the fee for a youngster who played fewer than 50 times for Shakhtar, but early signs suggest it may be money well spent. The jet-heeled attacker may add much-needed venom into a predictable attack. It may someday be considered a bargain.
