A month is all it takes for a team to work out what weaknesses it failed to address in the transfer window, or to realise who doesn't feature in their long-term plans.
The transfer speculation is already heating up as glaring holes in rosters are spotted or if it becomes clear a club has too many personnel for one position.
Read on to find the 20 most exciting transfer rumours currently doing the rounds.
No better place to start than Santos, Brazil where a certifiable superstar plies his trade.
Rumours surrounding Neymar's potential arrival in Europe have been raging for some time now, but it has become genuinely feasible that he dons a Barcelona or Real Madrid shirt come January.
Peixe coach Murciy Ramalho has added fuel to the fire by admitting to reporters he would advise the Selecao star to leave should he ask his opinion (via Soccernews.com.)
It's time for Neymar to depart South America.
Maybe it wasn't worth the trouble keeping Fernando Llorente at Athletic Bilbao this summer.
With the latest episode of Rey Leon vs. Marcelo Bielsa containing a training ground bust up to sour things further, the striker probably can't wait for January (via Goal.com.)
His contract ends in the summer of 2013, meaning he's free to talk to clubs this winter and would be available for a very reasonable fee.
Expect tremendous interest.
What on earth is wrong with Paris Saint-Germain's management?
Les Parisien's star player last season, Nene, has been completely frozen out of the side this season and seems to be on his way towards the exit.
The Brazilian, who scored an outrageous 21 goals and recorded 11 assists from midfield last season (via WhoScored?,) doesn't see eye to eye with Zlatan Ibrahimovic and could be set for a cut-price departure given his age.
Angelo Ogbonna is one of the hottest defensive properties on the market right now, as his current club, Torino, don't stand a chance in repelling a big bid for their vice-captain.
He was an unused substitute in Italy's Euro 2012 run and, according to SkySports, is a primary target for Sir Alex Ferguson in January given Manchester United's defensive woes.
WhoScored?'s Adam Digby has done a rather good piece on him here if you're not familiar with the name.
Florent Malouda refused to leave Chelsea this summer because he wanted to play in the Club World Championship in December.
He didn't really figure in Roberto Di Matteo's plans, so he's currently training with the reserves until he decides to pack his bags.
SkySports reckon Lyon could be prepared to take the Frenchman back to his home country this January—a story that brings a smile to the face of most Blues fans.
Andrey Arshavin is an unwanted man.
This summer, The Telegraph reported that Arsenal were prepared to let him go for free just to rid him from the wage bill, but the picky Russian still couldn't find a new home.
He's featured exclusively on the bench for Arsene Wenger this season, so it's arguable that the Gunners will try to shift him along again in January.
Ashley Cole's future will be under the spotlight this January as, like Fernando Llorente, his contract expires next summer.
He's already rejected a one-year extension with Roberto Di Matteo's Chelsea and there seem to be several rival clubs circling with menace.
Paris Saint-Germain coach Carlo Ancelotti has expressed his interest in bringing him to the Parc des Princes (via The Guardian,) but it seems the England international wants a long-term contract with the Blues (via ESPN.)
Chelsea's policy of refusing to offer long-term contracts to players 30 years old and above irks the former Arsenal left-back, but stubbornness on the part of Roman Abramovich could see Cole seek pastures new.
Lucas Digne is one of the world's premier young left-backs emerging through the ranks at Lille.
His performances, both domestically and on the continent, have been superb so far this season, prompting suggestions he'd be a good fit at a top European club.
The Daily Mail reckon Manchester United and Chelsea, among others, are looking closely at the kid, who could serve as a long-term solution to their respective Patrice Evra and Ashley Cole issues.
Demba Ba has started the season on fire, outscoring his Senegalese strike partner Papiss Cisse by six goals to zero.
His reported £7 million buy-out clause expired at the end of July 2012, but that hasn't stopped rival clubs expressing their interest in the hit man.
Negotiations for a new deal at the Sports Direct Arena aren't going so well (via The Daily Mail) and it seems Liverpool, among others, are taking notes.
The Reds, in particular, are desperate for a goalscoring threat and could find the Newcastle man an ideal fit for their squad.
The Theo Walcott saga has already bored everyone to death, but it's certain to continue over the next few months.
Contract negotiations have stalled between player and club, prompting fervent speculation that the England international will move to a club who promise to play him as a central striker (via Mirror Football.)
Arsenal fans appear split down the middle regarding whether or not he deserves a new contract with bumper wages, so the fallout from the eventual decision will be well worth keeping an eye on.
The curious case of Nani continues.
The Portuguese winger seemingly "almost" leaves Manchester United during each and every transfer window, and this summer played host to the most dogged rumours yet.
He was reportedly close to a move to Zenit St. Petersburg last month but couldn't agree personal terms, while Juventus have also been credited with an interest (via Mirror Football.)
The Russian powerhouses may just revisit this particular option.
Kevin Strootman has been labelled the next Roy Keane. While that comparison is farcical at best, the potential is there for the Dutchman to become a real English Premier League star.
His agent has suggested the player is ready to depart PSV Eindhoven during the January transfer window and the price is believed to be around £15 million (via The Metro.)
Manchester United are in need of an imposing central midfielder so this could be a wise pickup, but don't expect the Keane comparison to amount to anything.
Isco has been an absolute revelation for Malaga so far, bagging his first domestic goal at the weekend and continuing to impress in the UEFA Champions League midweek.
The Spaniard is already being linked to some of the top clubs in Europe. The Mirror Football believe he has a £16 million buyout clause which clubs could look to take advantage of in the winter transfer window.
Los Boquerones seem resigned to his eventual departure, and as many as five English Premier League clubs have been credited with an interest.
Nelson Oliveira was a surprise inclusion in Paulo Bento's Euro 2012 squad initially, but by the end of the tournament fans were calling for him to get a start.
Helder Postiga and Hugo Almeida were so underwhelming, Portuguese football fanatics wanted a relatively unproven 21-year-old to feature in the semifinal against Spain.
He belongs to Benfica, although he's on loan at Deportivo right now, and would command a huge fee should clubs come in for him.
According to talkSPORT, several English Premier League clubs are willing to take the plunge.
AC Milan could be in line for another tumultuous window as their newest starlet, Stephan El Shaarawy, has been linked away from the rapidly declining Italian powerhouses.
Goal.com reports that Adriano Galliani is desperately hoping Sir Alex Ferguson's admiration doesn't manifest itself into a prospective purchase, as their young striker is on the verge of nailing down a permanent first-team berth.
The one-cap Italian is worth watching this winter.
Marouane Fellaini has made a blistering start to the season and his move to the support striker position is a masterstroke by David Moyes.
His current role—that of the "suffoco"—has seen him put in some world-class performances in an unfamiliar area of the pitch.
The Belgian has been a fan favourite at Goodison Park for several seasons now, so it shocked the world when he declared he may be in his final season with the club (via The Daily Mail.)
Can Moyes pull off a second masterstroke by keeping him?
Colombian striker Radamel Falcao turned some heads with his performance against Athletic Bilbao last season in the UEFA Europa League final.
His predatory instincts have continued to impress and after blitzing Chelsea in the European Super Cup, the former FC Porto star will likely become the next >£45 million transfer.
Seven goals in five appearances so far this season proves he's consistently deadly, and Atletico Madrid might lose him sooner rather than later.
The player's father has fuelled speculation regarding a possible Real Madrid transfer (via SkySports,) while Roberto Di Matteo is reported to be interested after the beating his side received at his hands (via The Daily Mail.)
Fiorentina managed to hold onto their most prized asset in Stevan Jovetic again this summer, as the deadline day swoop Manchester City made in Florence was for Matija Nastasic instead.
Goal.com report that the Montenegrin has been told he can leave the Stadio Artemio Franchi in 2013, and while Viola will have the end of the season in mind, their resolve will likely be tested in January.
The vice-captain is enjoying another fine season so far having bagged four goals from seven appearances, while he's also chopped his mop.
With Tottenham Hotspur just "minutes" from securing a deal for Joao Moutinho in the summer transfer window (via The Telegraph,) it's probable that Andre Villas-Boas will launch another attempt to land his former captain.
It'll be interesting to see if any other teams in need of a playmaker try to land him, but Spurs are pole position.
Do Spurs need Moutinho?
Back in June, The Metro reported that Arsenal were preparing a £10 million swoop for Atletico Madrid's other brilliant striker Adrian Lopez in case Robin van Persie departed.
The latter happened, the former didn't.
The same paper now report that the Spaniard is stalling on contract negotiations amid possible interest from the Gunners and Spurs.
What's actually happening here is anyone's guess, but one thing is certain—Lopez would be a great signing for either of the North London clubs.