Chelsea have told a host of players, including Callum Hudson-Odoi, that they cannot seek loan moves after encountering issues negotiating for both Sevilla's Jules Kounde and Atletico Madrid's Saul Niguez.
In the case of Saul, the Blues are keen to do a deal if it can be done as a straight loan but the Spanish champions want a clause that makes it likely to become a permanent deal for £34 million ($47m). The 26-year-old is keen to move to Stamford Bridge.
Meanwhile, for Kounde, Chelsea have found Sevilla have taken a non-negotiable stance and are requesting €65 million (£56m/$77m). The Blues have arguably weakened their negotiating position by selling Kurt Zouma to West Ham for £29.8m ($41m) without a guaranteed replacement.
How does it affect outgoings?
Even though the Blues can force through a move for Kounde using his release clause, they will likely wait until the final hours of the window in a negotiating 'cat and mouse' game.
With doubts over a deal for the 22-year-old, Callum Hudson-Odoi's proposed switch to Borussia Dortmund is among the moves being blocked, while Ruben Loftus-Cheek's situation is also tied to Saul.
Hudson-Odoi is open to joining the German giants after being an unused substitute in Thomas Tuchel's first three games, but the Blues manager wants the 20-year-old around as cover.
Ethan Ampadu has also been told that he will remain at the club and will not be able to seek a loan move, with his situation linked to Kounde developments.
What deals will go through?
Tiemoue Bakayoko's move to AC Milan will not be blocked by the situation and will soon be announced.
The Blues are set to earn €1 million per year from the deal and a further €1 million if Milan qualify for the Champions League. There is a mandatory €17 million (£15m/$20m) purchase option under certain conditions.
The likes of Malang Sarr, Danny Drinkwater, Ross Barkley and Lewis Baker will be allowed to leave regardless of situations elsewhere.
Additional reporting by Paco Rico in Seville.