Andre Villas-Boas claims it will be "impossible" for Tottenham to sign Porto playmaker Joao Moutinho before the transfer window shuts tonight.
Spurs are renowned for their last-minute forays into the transfer market. Last season they snapped up Scott Parker on deadline day and the year before they made a sensational swoop for Rafael van der Vaart.
Moutinho was expected to be the focus of their attention today, but Tottenham appear unlikely to sign the 25-year-old due to a 40million euro (£31.7million) release clause in his contract.
"It's an impossible deal for the club," Villas-Boas told a press conference.
"You have to bear in mind that this is a player with a 40million euro release clause.
"This volume of money is out of Tottenham's possibility.
"Bearing in mind that this is a key player for club and country, you wouldn't say that you would get him at half the price and half the price is already bigger than Tottenham's record fee."
Villas-Boas may have already signed Jan Vertonghen, Gylfi Sigurdsson, Mousa Dembele and Emmanuel Adebayor this summer, but he is still expected to be an extremely busy man today.
The 34-year-old has ruled out moves for Loic Remy, Nani and Anderson, but did admit yesterday that he was keen to sign Lyon goalkeeper Hugo Lloris.
Shakhtar Donetsk's Willian remains another possible purchase, but like Moutinho, Villas-Boas fears Tottenham could be priced out of the market for the player.
"We had initial contact with Shakhtar, (who) again (are) a club in a position with wealthy owners, (and are) not easy to deal with," Villas-Boas added.
"We can't say that it's over but we have approached the club and at the moment it's a deal that doesn't seem to be happening."
Should Lloris arrive, one of the club's back-up goalkeepers like Heurelho Gomes could depart while there are also questions marks over the futures of Danny Rose, Jermaine Jenas, Tom Huddlestone, David Bentley and Giovani Dos Santos.
Van der Vaart could also leave, but only if Hamburg increase the £8million offer they tabled for the player last week.
"We have had interest from Hamburg, but an offer of that dimension is not something the player deserves," Villas-Boas said.
"Tottenham should be respected as a club. (The transfer) doesn't seem to be happening."
Michael Dawson appears unlikely to leave White Hart Lane after fellow centre-back Younes Kaboul was ruled out for up to four months with a knee injury yesterday.