With the January transfer window in full motion, there is plenty of business going on behind the scenes at clubs all over Europe.
Here, we take a look at some of the high-profile manoeuvres from both clubs and players that will have an impact on top clubs in this current market and beyond.
West Ham Fight to Keep £50M Marko Arnautovic
West Ham United are fighting to keep striker Marko Arnautovic at the club but are putting a £50 million valuation on him as the player pushes for a move to China.
Arnautovic's brother and agent, Danijel, has been driving a potential move to Shanghai SIPG, much to the frustration of senior figures at London Stadium, and the player has had his head turned by the prospect of a huge pay day.
The Austria international could earn as much as £220,000 tax-free if he made the move to Shanghai, and the 29-year-old has been so keen to take the money on offer that he even appeared to wave goodbye to fans on his last Premier League appearance.
Arnautovic is concerned the Chinese Super League club are going to soon move on to other targets, but the Hammers dismissed an initial offer of £35 million and would ideally keep the player. They edged closer to an agreement at £45 million but Stoke City are due a 20 percent sell-on, and there will also be high agents fees. With that in mind, the deal has not yet been agreed.
Sources at West Ham believed he could be convinced to stay if they offer an improved contract. He is currently picking up around £100,000 per week—and the current top earner is Javier Hernandez on £140,000 per week. But it seems unlikely he will play this weekend so his long-term future remains unclear.
Edin Dzeko and Olivier Giroud on West Ham Wanted List
West Ham are on the lookout for a new striker in case they lose Arnautovic, with Edin Dzeko and Olivier Giroud high on their list of potential replacements.
Maxi Gomez from Celta Vigo has been the name at the top of their agenda, but it appears he will prove too expensive, so they are looking into other options, including loan deals.
Dzeko is someone they have had interest in for some time, and Hammers manager Manuel Pellegrini is on board with trying to bring him in from AS Roma.
And Giroud's lack of game time at Chelsea has given them hope he could be encouraged to push for a move if they make their intent known.
Another West Ham forward, Lucas Perez, is still hoping to seal a switch away from the club this month, and he has his eyes on Spain as the next destination.
His time in the Premier League with Arsenal was unsuccessful, and he has failed to make much impact in the east end of London since joining West Ham in August.
Perez has a three-year contract but could be allowed out on loan initially.
Cengiz Under Will Leave AS Roma
The future of Cengiz Under has been an ongoing concern at Roma, and while they will keep him at the club beyond this transfer window, it is expected he will be sold in the summer.
The Turkey forward earns less than £20,000 per week in Serie A, and his representatives have been exploring channels within the club to see if they could give him a rise to match his status.
No agreement has been reached, though, and it is now accepted within Roma that Under can leave if another club matches his valuation, which is likely to be around £40 million.
The 21-year-old has a host of clubs interested, with Manchester United, Arsenal, Tottenham Hotspur and Bayern Munich among them.
At this stage, sources indicated Bayern are the most serious suitors, but the preference for the player would be a move to the Premier League.
Chelsea Transfer Policy Provides Test for Maurizio Sarri
Once Gonzalo Higuain pulls on a Chelsea shirt, head coach Maurizio Sarri will find himself under new pressure.
He is already battling to prove his style of football will work in the Premier League, and he managed to convince the club's hierarchy to go ahead with a move for his former Napoli player in order to get the Blues moving in the right direction again.
However, there are certain figures at the club who have been concerned about Sarri's style of management and do not feel Higuain is the right fit for where they want to take the club.
Time will now tell how he fits in but if the Argentina international flops, Sarri will find himself with less say in the next transfer window.
Meanwhile, Michy Batshuayi has been desperate to complete a move to AS Monaco because of the chance to learn from Thierry Henry.
Chelsea are blocking the move because they only want to do a permanent deal, and the Ligue 1 club would prefer a loan.
Batshuayi ended a spell with Valencia last week and has spoken to Henry about how he would fit into his plans at Monaco. He believes the switch could see him return to top form and still hopes Chelsea will allow a move to go ahead.
Liverpool Monitor USMNT Star Weston McKennie
United States international Weston McKennie has been turning heads with his performances at Schalke 04 this campaign, and he is firmly on Liverpool's long-term radar.
It is expected the 20-year-old would cost upwards of £25 million in the current market, but that value will soar if he continues to impress with displays in Bundesliga.
Liverpool scouts have been impressed with his midfield traits and will continue to monitor him with a view to a future move.
The club were also interested in his U.S. team-mate, Christian Pulisic, but they see similar a similar quality in McKennie on the field and also believe his commercial value will be huge.