The winter transfer window is open and negotiations on new signings are under way, so we are taking a peak at potential ins and outs that you need to know about for the month ahead.
By calling on Bleacher Report sources across Europe, we have been able to get insight on some of the big storylines that are likely to unfold.
We kick off with the fallout from a transfer that has already been confirmed in Germany...
1. The Erling Haaland Knock-On Effect
Borussia Dortmund have won the battle for Haaland's signature and we will now see how the result of that agreement is impacting the Bundesliga club and their European rivals.
The man most directly impacted is Paco Alcacer, the 26-year-old striker, who will seek a new home as his chances of game time are going to be very limited.
Haaland will be a guaranteed starter at Dortmund, and sources suggest that intermediaries working on behalf of Alcacer are already sounding out other clubs about a move. One of those is Atletico Madrid, who are in talks with Edinson Cavani but have not yet sealed the deal.
Away from that, it is Manchester United who are the club most affected by Haaland's decision to join Dortmund. They have to decide whether to now sign someone else, like Lyon's Moussa Dembele, or rely on Mason Greenwood to provide back-up to Anthony Martial and Marcus Rashford for the rest of the season.
2. The Battle for Jadon Sancho to Intensify
Haaland will be excited about the prospect of teaming up in attack with Sancho at Dortmund...but they won't be working together for long.
Sancho, 19, is likely to remain at the club for the rest of this season, but B/R sources have indicated it is very possible that an early agreement could be put in place for a summer transfer—similar to the way Christian Pulisic was signed by Chelsea one year ago.
Man United have their eye on Sancho and are thought to be keen on the idea of making an early offer for the England international, given they are not planning to spend significant money in January. But bear in mind that Manchester City have a buy-back option on Sancho—which means they will be given the chance to match any acceptable bid on the player.
Dortmund are going to seek a fee upwards of €100 million—a major rise on the €9.3 million they bought him for from City in August 2017. Liverpool are being kept in touch with any developments, but Chelsea are more likely to be tempted into such a big transfer.
3. Chelsea Return with Big Money to Spend
The Blues are bouncing back from a transfer embargo and have a £180 million transfer budget, according to sources. Boss Frank Lampard is hopeful of improving the side in at least two positions this month.
An early deal for Sancho would undoubtedly be their biggest business of 2020—and there is desire for a new wide attacker despite Callum Hudson-Odoi, Christian Pulisic and Willian looking part of their plans for the next year.
Chelsea also made checks on Wilfried Zaha—available from Crystal Palace at £80 million—but are not planning to pursue that unless the price drops by at least £20 million. Samuel Chukwueze of Villarreal and Leon Bailey of Bayer Leverkusen have also been scouted extensively.
A wide attacker is not the priority, though, as Lampard sees a new defender and central striker as more immediate fixes.
Bournemouth's Nathan Ake is almost certain to be the subject of an offer from Chelsea, and a £40 million buy-back clause should see that one go through. He can operate at centre-back, left-back or defensive midfield and would be a great asset in the second half of the season once fit again after a hamstring problem.
A striker is wanted to challenge Tammy Abraham for his place, and Dembele of Lyon is emerging as a major candidate. He is valued at around £40 million too. Chelsea will be opening up one of their forward slots by letting Olivier Giroud leave.
4. Arsenal Plan 2 Signings—and Won't Sell Pierre-Emerick Aubameyang
New manager Mikel Arteta is bringing renewed energy, work rate and drive to the club, but he also needs some additional quality in his squad if there is to be any vast improvement from Unai Emery's reign.
To that end, Arsenal are willing to help their new boss in the window by actively pursuing a new defender and central midfielder.
Various options have been explored in terms of the defence, with Merih Demiral of Juventus and Dayot Upamecano of RB Leipzig two of the names they have looked at. The issue with both is that the players prefer the status of the club they are already playing for.
It could be that Arsenal bring William Saliba back from a loan at Saint-Etienne instead. The 18-year-old was signed in the summer but loaned back to the French club as part of the deal.
In terms of midfielders, sources told B/R to remain cautious over a big name arrival like Thomas Lemar or Adrien Rabiot, who have both been linked. But there is a belief that the Gunners will strengthen, and one contact suggested they might be one of the clubs enquiring about Lille's Boubakary Soumare.
As for Aubameyang? He's going nowhere yet. There is concern about whether he stays beyond this season, but the board are not willing to entertain the idea of him leaving halfway through this tricky campaign.
The same goes for Mesut Ozil. There will probably be rumours over his future, but he is going nowhere.