Like winter frost or summer warmth, the January transfer window creeps along the football calendar at the same time each year as a clear indicator of where we stand as a sport in the grand scheme of things.
Or even, like a World Cup Final, FIFA scandal or Zlatan Ibrahimovic hat-trick, the January transfer window makes all of football sit up, take notice and subsequently think long and hard about where it stands.
This week we take a closer look at a certain aspect of this beautiful sport, the German Bundesliga, and try to decipher just how and where some of the world's greatest talents plan either to leave or join the illustrious league.
We've also included a small grading system, from A to F, based on how likely we think each deal is to going through in the coming months.
In just the last few hours prior to this article getting published, the English press, specifically the Daily Telegraph and the Daily Express, have run prominent stories linking the towering Brazilian defender with a move to the European champions in Munich.
Bayern are in need of another central defender, with only Dante and Jerome Boateng offering proper alternatives whilst Holger Badstuber recovers from his serious, long-term injury, and as heavily reported in the summer prior to the new season, Pep Guardiola seems very keen on acquiring the Stamford Bridge star.
In an interview with the Sun, as reported in the aforementioned Daily Telegraph link, Luiz talks about rejecting a move to Barcelona in the summer but doesn't speak at great lengths about any proposed move to Bayern.
Whether or not that is due to his hope of any such move is yet to be seen, but it wouldn't be the most far-fetched of transfers.
A player who could yet move the opposite way from Luiz is Gladbach midfielder Granit Xhaka who has again been linked with an interesting move to Liverpool, after initial reports from last February—as seen here in Metro—began to resurface throughout the English press.
Xhaka is undoubtedly talented and was initially signed by Gladbach coach Lucien Favre as a long-term replacement to Roman Neustadter last season, yet the central midfielder had a very disappointing debut campaign in the Bundesliga and, as a result, undoubtedly fell off the radar of a number of clubs in the summer.
Yet he's back this season and finally looks the player the Foals so readily forked out their cash for. The only problem is if they would be willing to let him go after sticking by the box-to-box midfielder last year.
We doubt it and, as such, he is unlikely to be going anywhere this January.
With rumours going as far back as last summer, as reported by the Daily Mirror here, it seems a foregone conclusion to suggest that Marc-Andre Ter Stegen will one day play for Barcelona.
The young Gladbach shot-stopper has been a first-team player longer than he's been allowed in to the club bar and is undoubtedly one of the most comprehensive goalkeepers in Europe despite only being 21 years old.
Unfortunately, Gladbach are the kind of side who are more than used to seeing their stars move on to bigger, brighter lights and, as such, any potential bid from Barcelona is likely to be accepted by the club one way or another.
Maybe not a deal to be done in January, but certainly one for the near future.
As reported by our very own site here, amongst numerous others throughout the press, it seems as though one can't walk down the street these days without a rumour linking Julian Draxler to the English Premier League slapping you in the face.
Despite signing a comprehensive new deal at Schalke in the summer, the concept of a fairly common minimum fee release clause in excess of £40 million continues to pour gasoline on the lit flame of every transfer report surrounding the player.
Yet in light of a shaky national side spot for this summer's coming World Cup, any potential move does run the risk of a drop in game time and his place in Joachim Low's plans for the future.
As such, despite the absolute fanaticism surrounding any deal, we can't see this happening in January.
Although Robert Lewandowski's proposed move to Bayern Munich in the summer is all but documented and near enough codified at this point, the prospect of the Polish goalscorer making the quick move south this January isn't entirely impossible.
Dortmund would fight tooth and nail to retain the striker's expertise in the midst of a tough season, yet Jurgen Klopp is a pragmatic man.
And alongside the fact that his two new forwards, Pierre-Emerick Aubameyang and Henrikh Mkhitaryan, have both strolled into the side with relative ease, one could suggest that Dortmund are a lot better placed to live without their once-sole source for goals than they were six months ago.
Similarly, the situation at Bayern suggest change may be at hand, too, with Pep Guardiola showing a consistent disdain for current striker Mario Mandzukic, often opting to leave him out of the starting line-up altogether. Guardiola needs a new striker and he's not the kind of man to wait about.
Robert Lewandowski may yet be wearing the dark red of Munich a lot sooner than we all think.
As reported by Bleacher Report here on a daily basis at the moment, the ongoing fever surrounding Marco Reus and a number of English and Spanish clubs has been heating up for some time in the hope of boiling over in the midst of the January transfer window.
The Dortmund star has been linked with all sorts, from PSG to Barcelona and even to Arsenal and Manchester City.
Yet the one club that has continued to stick through the procession of stories throughout the English press is Manchester United and particularly David Moyes' admiration for the player.
Unlike the flimsy scenario that may surround Robert Lewandowski's proposed move out of the club, Reus is undoubtedly a loyal dog to the Klopp campaign and would take significant convincing, alongside a sizeable sum of money, to force him even to consider a move away from Dortmund at the moment.
Equally, Reus is a mainstay of the German national side and would be quite content keeping things as they are to avoid any risk of losing his role in the team ahead of the World Cup. Manchester United may come knocking, but Reus just isn't ready to leave home yet.
In a similar manner to the current rumours surrounding Granit Xhaka's suggested move to Mersyside, Xherdan Shaqiri has been linked with a transfer to Liverpool off the back of what can only be suggested as old recycled news.
We obviously kept track of such rumours for you last summer, here, when the news was still hot, but as of yet nothing substantial has came from any of the English or German main press to suggest that the Bayern forward may well be on his way to England (again).
Yet that's not to say that he couldn't still go.
Shaqiri was clearly an interesting prospect to the Liverpool management over the summer, as he should be considering his abundant talent and modest squad status, and it would perhaps prove rather wise for the English Premier League club to test the water and again consider pursuing the player.
A potentially excellent move but no substance behind it as of yet.
As linked with a move to Chelsea in not only the Metro but Sky Sports, too, in the past couple of months, highly sought-after left-back Ricardo Rodriguez will undoubtedly be one of the Bundesliga hottest transfer prospects this coming January.
The Wolves defender is obviously being considered as a potential replacement for club favourite Ashley Cole in his preferable full-back position and may just offer a perfect solution.
Rodriguez has been in outstanding form for his club during one of their best-ever starts to a Bundesliga season. Deiter Hecking's side are on the verge of a Champions League spot and it's entirely down to the European calibre in their side.
What's more, Wolfsburg's general manager Klaus Allofs, a man who can rarely keep his opinions to himself, was quoted as saying that it would be "a great thing" to have clubs such as Chelsea sniffing around some of his promising players. Hardly a barking order to go get lost, Jose.
An excellent player at a club who would probably be rather comfortable exchanging his services for a bump in the bank balance. This rumour has some sense behind it.
Ilkay Gundogan confirmed himself as one of the best young midfielders in European football last season with a consistent string of performances for Borussia Dortmund as they marched to the summit of the Champions League.
As such, rumours of any potential deal were rife throughout the summer, yet the fledgling wonderkid had his heart set on continuing his current trajectory with Dortmund and that seemed to be that.
Then the Guardian decided to run an interesting story linking the midfielder with a move to Arsenal in November for around £25 million and, all of a sudden, we were back to square one.
Yet the logistical problems that Arsenal would initially face—besides Jurgen Klopp offering to fight them for his player's signature—is, of course, the fact that Gundogan hasn't played a moment of proper, competitive football for Dortmund this season and could, of course, spend the entire transfer window on the injury table.
If he were fit, playing and raring to go, a proposed move to Arsenal would make a lot of sense for a number of reasons, yet such a move for a player in his condition at the moment just doesn't add up.
Another Wolfsburg player who has been heavily linked with a move to the English Premier League is attacking midfielder Diego.
The Brazilian playmaker is undoubtedly one of the best players currently plying their trade in the Bundesliga at the moment, but as we've seen in the past, the flamboyant midfielder has rarely been discreet about his desires to play near enough anywhere else.
In an interview with the Sun, that was covered here by Sky Sports, Diego spoke of his love for Arsenal, the interest they had supposedly shown in him and how eager he would be to sign for them as well as playing alongside his old team-mate Mezut Ozil.
Yet it has been another English side who have been linked with his services, Southampton to be particular, and despite Mauricio Pochettino's insistence that the rumour is no more than exactly that, such a deal seems to make a lot of sense for the Saints and the 28-year-old star.