Chelsea remain the club you can't take your eyes off this window - but could they be about to be handed a major transfer blow?
Just when it appeared a deal to bring in midfielder Leandro Paredes was close to completion, they have been hit by a bolt from the blue.
Paris Saint-Germain have emerged as serious rivals - and if reports coming out of Italy are correct, they've already blown them out of the water.
Friday has already provided plenty of talking points ahead of the weekend action.
To keep track of all the latest transfer news and gossip throughout the day, follow our live transfer blog here .
And to see every completed Premier League transfer so far, click here .
Here are four key transfer stories that you may have missed so far today…
Paredes problem for Chelsea
Chelsea risk losing out on Leandro Paredes as Paris Saint-Germain look to hijack the deal.
Maurizio Sarri sees the Zenit midfielder as an ideal replacement for Cesc Fabregas.
But reports in Italiy via Gianluca Di Marzio say PSG have already put forward a €35 million offer.
Chelsea have lodged a bid of around £27m with Zenit for the midfielder but the Russian club have held out for closer to £40m.
It's a fresh twist to the saga after the 24-year-old recently retweeted a video appearing to introduce him at Stamford Bridge.
West Ham's Arnie relief
West Ham fans have had the news they really wanted.
Striker Marko Arnautovic will not be moving to China this January and the deal is off.
The striker was the subject of a £35million bid from an unknown Chinese Super League club.
Bit it is now understood that they will not be coming back with a second bid and they have pulled out of the running.
Suarez hint dropped
Denis Suarez has dropped a huge Arsenal hint - well, his girlfriend has.
Model Nadia Viles Garcia has been spotted on London and also posted from the capital on Instagram .
The Gunners are desperate to sign Suarez from Barcelona this window.
It's the biggest nod yet towards the deal being done as manager Unai Emery attempts to bolster his squad.
Fellaini falls foul
Marouane Fellaini is staying at Manchester United . The midfielder has been sidelined for up to four weeks - ruling him out of a January move.
United were ready to listen to offers for Fellaini, who has played just 31 minutes under Ole Gunnar Solskjaer.
But a calf injury has ruled the AC Milan and Porto target out until February.