...so Louis van Gaal really needs to get his thinking cap on. Does he abandon his favourite formation to make room for Adnan Januzaj? It's also big for Arsenal's Germans and Big Sam.
After the departures of Diego Costa, Filipe Luis and Thibaut Courtois to Chelsea, plenty are saying Atletico Madrid won't retain their title. Tim Stannard thinks otherwise...
10) Zlatan Ibrahimovic to Arsenal
Before breaking into the Malmo first team at 16, a young Ibrahimovic would often be seen wearing an Arsenal shirt, and was firmly on the club's scouting radar. As Arsene Wenger recalls, the club made significant efforts to sign the striker.
"It is true," Wenger admitted. "I went there to meet him and to see him training but he did not want me to meet him. You cannot buy a player you do not see."
Typically, Zlatan himself has a different version of events. "I waited for him to convince me that I should join Arsenal," the Swede wrote in his autobiography. "But he didn't even try. He never actually made me a serious offer, it was more, 'I want to see how good you are, what kind of player you are. Have a trial'. I couldn't believe it. Zlatan doesn't do auditions."
9) Michael Essien to Burnley
Essien may have cost Roman Abramovich £24.4million when he joined from Lyon in 2004, but Burnley was in fact the first English club to show a serious interest in the Ghanaian as early as 1999.
Essien had been one of the stars of that year's Under-17 World Cup, and had arrived at Turf Moor available on a free transfer. As owner Brendan Flood now reveals, the club's miserly pay structure meant that they missed out.
"I discovered Michael Essien had been on trial here for a few days," Flood told The People. "The club policy meant we wouldn't pay an apprentice more than 60 quid a week. It smacked me in the face that the problem was a lack of communication within the club that stopped our youth guys making an exception to the rule."
Wonderful cutting off of nose to spite face.
8) Rivaldo to Bolton
The Sam Allardyce years at Bolton brought the likes of Youri Djorkaeff, Jay-Jay Okocha and Ivan Campo through the door, but the club came very close to adding World Player of the Year Rivaldo to that list, when in the summer of 2004 all looked in place for a move to bring the Brazilian in from Milan.
"With a transfer of this size you can never be 100% sure but things are going very well," Simon Harrison [Rivaldo's English representative] told the Bolton Evening News. "There's nothing untoward about the delay. Rivaldo just wanted time to think about it. I know for sure that Sam made a good impression on him and so did Phil Gartside. Everything's looking good."
Even better was the quote from Kevin Davies: "You've got to work hard in this team. We've had good players but they have not worked hard and been left out. Let's see how good he is at tracking back."
Sadly, we never had chance to find out, as the 32-year-old instead chose a move to Greek side Olympiakos.
7) Paul Gascoigne to Manchester United
The one that got away for club, country and player himself.
With both Spurs and Manchester United competing for Gascoigne's signature, Alex Ferguson thought he had secured a deal, with the player assuring Fergie that he would sign. Less than 24 hours later, though, and Gascoigne had joined Spurs, with the club's promise to buy the player a house the turning point in the move.
"Alan Shearer is one I wish I'd signed, but for me the most disappointing of all was Paul Gascoigne," Ferguson admitted when discussing his biggest regrets at Old Trafford, while the player also has similar feelings of remorse. "He always says one of his greatest regrets was not signing me, but I think it was the other way round, me not signing for the guy," Gascoigne told Sky Sports News.
The biggest English talent of his generation could have been so much more.
6) Cristiano Ronaldo to Arsenal
When still at Sporting Lisbon, Ronaldo was not only shown around Arsenal but also given a club shirt with his name on, with Wenger revealing just how close he came to sealing a move.
"He was very close to coming here. He has a number nine shirt with Ronaldo on the back from Arsenal Football Club," Wenger told an ITV documentary. "What happened was that Carlos Queiroz went to Manchester United and they snapped him away from us because he knew him from Sporting."
Even the player himself admitted his fondness for a move, who even took his mother to meet the club. "'I met Arsene on three occasions and one of those times was with my mum, who wanted to hear what he was proposing. The contact we had with him and Arsenal meant it was very close to being a done deal. Really, we were within touching distance."
Still, Wenger ended up paying more money than the Ronaldo fee on Jose Antonio Reyes, so not all bad. Ah.
5) Ronaldinho to St Mirren
With Ronaldinho already having a deal in place to join Paris Saint-Germain in the summer of 2001, the Brazilian had made clear his intention to move to northern Europe in order to prepare for the climate and way of life. Amazingly, struggling SPL side St Mirren soon became the favourite to sign Ronaldinho ahead of many other suitors, with a deal days away from completion.
However, a fake passport scandal back in Brazil delayed a deal, and the Brazilian FA eventually ruled out the club's hopes of an astonishing coup.
"We spoke about Ronaldinho but there was a legal problem at the club he was at," then manager Tom Hendrie explained. "Because of the problem, the Brazilian FA would not release the player's international clearance in time for us to register him ahead of the deadline."
4) Eric Cantona to Sheffield Wednesday
Manchester United fans still love to sing the '12 Days of Cantona' between November and February, but it could all have been so very different.
In 1992, Trevor Francis brought a young Cantona from Nimes in order to give him a trial in England, including the Frenchman's participation in an indoor friendly match (as evidenced here).
Francis was impressed, but asked his potential new signing to stay on for a further week-long trial in which his performance in a friendly game on grass could be judged. Offended by the request (he had also played almost 200 league games in France), Cantona told Francis where to stuff it and joined Leeds. They went on to win the League Championship and Eric moved on to famed effect.
3) Michael Laudrup to Liverpool
Perhaps still slightly underrated in his greatness, Laudrup was a player for which the cliche 'a football brain' was invented, such was his ability to read (and execute) the perfect pass, dribble or shot. As the great Franz Beckenbauer once said: "Pele was the best in the 60s, Cruyff in the 70s, Maradona in the 80s and Laudrup in the 90s."
Unlike his brother Brian, Michael never played in England, but came extremely close to joining Liverpool from Danish side KB in the early 1980s. A deal was agreed between the two clubs with the midfielder agreeing to a three-year contract, only for Liverpool to change their minds and insist on the contract length being extended to four years.
The stipulation gave Laudrup cold feet, and shortly afterwards he turned down a move to Anfield and instead went to Juventus and began to set Europe alight. Not literally.
2) Zinedine Zidane to Blackburn Rovers
The quote that should be remembered for eternity: "Why do you want to sign Zidane when we have Tim Sherwood?"
Blackburn Rovers owner Jack Walker is the man reported to have uttered such words, and whether they are accurate or embellished over the passing of time, the point still stands true - Blackburn pulled out of a deal for a Bordeaux player who would go on to become one of the game's greats.
Manager Kenny Dalglish was desperate for a double deal for Zidane and Christophe Dugarry to be completed but, with the board refusing to sanction the fee, it fell dead in the water. The pertinent question remains this: Could Zidane get the best out of Nabil Bentaleb?
1) Diego Maradona to Sheffield United
The day Sheffield United would never again be the same. The Blades may have held greatness in their hands with the likes of Dean Windass, Mitch Ward and Robert Page, but the arrival of Diego Maradona would perhaps have eclipsed even those three.
In 1978, manager Harry Haslam went to Argentina on a scouting mission for new (and cheap) talent in order to get the club out of Division Two. Whilst there he spotted a 17-year-old Maradona and, being hugely impressed, agreed a £200,000 deal to sign the youngster.
However, with the club's hierarchy refusing to stretch to such a fee, Sheffield United instead bought Alex Sabella - now Argentina coach - for £160,000, meaning that they missed out on perhaps the game's most talented player ever. They can't even blame this one on Carlos Tevez.
Daniel Storey - Follow him on Twitter
If Maradona had gone to Sheffield United at 17 they would have told him to play it square all the time, none of that fancy stuff or you're out son. He would have become David Batty.- the duvel