Paris Saint-Germain were hoping to complete a move for France striker Randal Kolo Muani from Eintracht Frankfurt on Friday in what would be the biggest deal to go through on transfer deadline day in Europe.
The 24-year-old forward, who hails from the Paris suburbs, has been a target for PSG all summer and is keen to join the French champions.
He missed training with Frankfurt this week, with the German side confirming "his desire to be transferred to another club before the transfer window ends on Friday evening".
Kolo Muani, who signed for the Bundesliga club from Nantes only a year ago, played no part in Eintracht's 2-0 home win over Bulgarian side Levski Sofia on Thursday that saw them seal a place in the Europa Conference League group stage.
However, up until Friday morning Frankfurt had rejected PSG's proposals for a player who is under contract at his present club until 2027.
It is understood that the Ligue 1 side have attempted to offer their out-of-favour forward Hugo Ekitike to Eintracht as part of any deal, as they look to team Kolo Muani up with fellow French internationals Kylian Mbappe and Ousmane Dembele in their attack.
Any chances of Mbappe leaving PSG in this transfer window faded after he returned to Luis Enrique's team in August, ending a contract dispute that had dominated headlines all summer in France.
Mbappe's contract expires at the end of this season and PSG had previously said the 24-year-old must agree to be sold in the window unless he signed a new deal.
"Kylian is a PSG player. We are having really good discussions with him," club president Nasser al-Khelaifi told broadcaster RMC on Thursday in Monaco after attending the draw for the Champions League group stage.
"He is a magnificent player, as a person and as a professional."
"We are going to work on it and try to do something," Khelaifi added, before saying he did not want to talk about Mbappe possibly signing a contract extension.
PSG have spent in the region of 250 million euros ($270m) on new signings in this window, including 60 million euros on Uruguay midfielder Manuel Ugarte from Sporting of Portugal.
SAUDI IMPACT
The Qatar-backed club have spent comfortably the most of any club in Europe outside the Premier League since the transfer window opened in June.
That is despite Bayern Munich dishing out a Bundesliga record of a reported 100 million euros to sign Harry Kane from Tottenham Hotspur, having earlier signed centre-back Kim Min-jae from Italian champions Napoli.
The other major transfer of the European summer saw Real Madrid spend 103 million euros to sign Jude Bellingham from Borussia Dortmund.
As well as the usual drain of talent from the rest of Europe to the far wealthier English Premier League, clubs in major leagues on the continent have also had to deal with the new competition coming from Saudi Arabia.
The Saudi Pro League has made headlines with its spending, led by the reported 100 million euros paid to PSG by Al-Hilal of Riyadh for Neymar.
Others who have swapped Europe's major leagues for Saudi Arabia include Portugal winger Otavio, who joined Al-Nassr from Porto for a reported 60 million euros.
Al-Ittihad of Jeddah signed Brazil midfielder Fabinho from Liverpool for a fee close to 50 million euros, while Al-Ahli paid a similar amount to secure Gabri Veiga from Celta Vigo.
The latter move was one of the most ominous indications to the traditionally dominant European leagues that they can no longer expect to stockpile all of the best players.
While the likes of Cristiano Ronaldo and Karim Benzema were past their prime when they opted to move to the Gulf, midfielder Veiga is just 21 and only made his breakthrough in LaLiga last season.
More big moves from Europe to Saudi could still follow, with the transfer window there open until September 20 according to Fifa.