Top clubs don't always get transfers right, but which deals from history do we wish had worked out better than they did?
De Bruyne and then-Chelsea boss Jose Mourinho will tell you different stories about what happened to the Belgian at Stamford Bridge in 2012-14. Either way, De Bruyne made only nine appearances for the Blues before being shipped out on loan and was eventually sold to Wolfsburg for £18m. Now a world-class midfielder at Manchester City, his career has panned out pretty well since, so we wonder what he would've done under Mourinho? After all, he's quite a Mourinho style of player -- strong, direct, adaptable, tactically disciplined when required -- so it could have been a match made in heaven. And we won't even mention that Mourinho later made the same mistake with Mohamed Salah. Oh wait, we did.
No one player could have halted the post-Sir Alex Ferguson slide at Manchester United, such were the problems at the club that were papered over by one man's genius, but when they spent a British record £59.7m on Real Madrid winger Di Maria in 2014, after a year of struggles under David Moyes, there was a genuine sense that this was a step back toward the big time. Di Maria's failure in England was partly down to injuries, partly down to his relationship with manager Louis van Gaal, but also partly because of the attempted robbery in January 2015 that reportedly affected him and his family so badly that they left England at the first available opportunity. Had a few things been different, he could have led a more convincing United revival. Instead he left for PSG a year later at a £15m loss.
8) Paul Gascoigne at Lazio
You could argue Gascoigne's whole career was one long "we wished it had worked out," but in particular the England midfielder's £5.5m move to Lazio felt like such a waste. Of course, it was doomed before he even arrived, a knee injury suffered in the 1991 FA Cup final while playing for Tottenham pushed the transfer back a year and when he did arrive in Italy, fitness problems stalked his every move. Of course, Gascoigne's issues did not stop at his cruciate ligament, and perhaps nothing could have saved him, but at a time when English football was emerging from its darkest period in a generation, having a genuine superstar succeed abroad would have been glorious.
7) Andriy Shevchenko at Chelsea
In the summer of 2006 it felt as if Chelsea had accessed a video game cheat code. Surely it wasn't fair to the rest of the division that the team who had won the last two Premier League titles be allowed to sign one of the world's best strikers for £30m. But what should have been a perfect pairing of a nouveau riche club and an aristocrat of a centre-forward didn't work. Having netted 127 goals in 208 Serie A games for Milan, Shevchenko struggled in England and could net only nine in 48 in the Premier League. Nothing especially dramatic happened, it's just that everything was a little off and his career petered out with a return to Ukraine.
6) Jonathan Woodgate at Real Madrid
At what point did you start to feel sorry for Woodgate in his three-year spell at Real Madrid? Was it during his infamously calamitous debut when he scored an own-goal and got sent off? Or was it before that, given he was able to make his debut only a year after signing from Newcastle for £13.4m in August 2004 after the smorgasbord of injuries that had dogged his career prevented him from playing? Woodgate could have been one of the great defenders of his generation had those injuries not scuppered things, and while he retains a tragicomic cult-hero status in Madrid, it's possible he could have been just a straight-up hero.
5) Gaizka Mendieta at Lazio
Very often the secret of a good transfer is timing, but Mendieta's €47.7m move from Valencia to Lazio in 2001 must be about the worst-timed ever. The midfielder left Valencia just after they had lost their second Champions League final in two years -- also the summer before Rafa Benitez arrived and won the first of their two La Liga titles -- and joined Lazio, at that stage only a year after they had won Serie A. He never adapted to Italian football, at least in part thanks to a team changing around him as their financial apocalypse closed in, and played 31 times for the club before being sent on loan to Barcelona and Middlesbrough, whom he later joined permanently. At his peak, Mendieta was a beautiful player, a classic midfield string-puller, running games in a low-key sort of way, and it would have been wonderful had his talent been rewarded with a major title.
4) Fernando Redondo at Milan
Argentina midfielder Redondo never wanted to leave Real Madrid, but he had the misfortune to be an excellent but relatively functional player at a time when the club needed to raise money to pay for more glamorous recruits. He was sold in the same summer of 2000 that Florentino Perez pulled off the great and extremely expensive Luis Figo heist from Barcelona, and the £11m that Milan paid for Redondo came in very handy to balance the books. Still, he could have been perfect in Italy, but ruptured his cruciate knee ligaments in an early training session for Milan, didn't play for two years and finally admitted defeat in 2004 when he retired at 35.
3) Robbie Keane at Liverpool
While the obvious jokes about how many boyhood clubs Keane had upon signing for new clubs are amusing, there is something undeniably romantic about a player signing for a club close to their heart. It should have worked too but, according to Steven Gerrard, Benitez bought Keane for around £20m from Tottenham and then immediately started trying to change his game, which seems an odd strategy for a striker who already had 170 goals to his name. Keane was at Liverpool for the first half of the 2008-09 season, when they finished four points behind Manchester United for the title, before returning to Tottenham. Could his goals, used properly, have tipped the balance? We'll never know.
2) Juan Sebastian Veron at Man United
In some respects, it's surprising that Ferguson even signed Veron: here was a manager who was a pragmatist, taking a £28.1m punt on a brilliant midfielder who quite obviously didn't really fit into his team. Ferguson occasionally couldn't resist a little romantic gamble, and while it paid off with Eric Cantona, it didn't with Veron, who spent two fruitless seasons with United. The club were ultimately lucky to get half of their money back because new Chelsea owner Roman Abramovich came along with £15m in 2003, though the Argentine ended up playing only seven times in the Premier League before being loaned to Inter and Estudiantes. United have had a few expensive failures over the years, but Veron combining with Paul Scholes, spreading passes out wide to David Beckham and Ryan Giggs, slipping through balls to Ruud van Nistelrooy would have seen their dominance extended for a few more seasons at least and could have landed them another Champions League trophy.
1) Mario Balotelli at Liverpool
None of Balotelli's transfers have really worked out. After three years at both Inter Milan and Man City, two years on the red side of Milan followed, before a £16m transfer to Liverpool in 2014. Most of the Italian striker's moves at least started with a bit of hope, but not this one. Manager Brendan Rodgers made it pretty clear from the start that Balotelli was basically a gamble because they couldn't get anyone else to replace Luis Suarez -- his first choice being Alexis Sanchez, who chose Arsenal instead. Four goals in 28 games ensured Balotelli was back on loan at Milan within a year, then on to Nice where it seemed briefly as if he had found somewhere relatively low-key to fulfil his potential. He never really has, but what a story it would have been had he succeeded at Anfield. It would have defied all logic, sense and conventional tactics, but it would have been fun.