Mauricio Pochettino assumes Danny Rose, Toby Alderweireld and Mousa Dembele will all remain at Tottenham beyond the end of the transfer window.
The trio have been linked with moves away from Spurs and teams in France, Germany and Spain can still buy players, despite the window having already closed in England.
However, Pochettino has revealed he is preparing as if there will be no departures from his squad this month.
"I am working like if all the players will still be here," he said at his news conference on Friday.
"I cannot work thinking if they are going to be here tomorrow or not. Not only these names [but] different names.
"Maybe tomorrow [Saturday] or this afternoon an offer arrives, [and] we will consider it.
United preparations. August 24, 2018
"You are focused on different names, but we are focused in trying and taking the best decision to provide them the opportunity to play if they deserve [to]."
Tottenham's next game is a trip to Old Trafford on Monday to face a Manchester United side under the microscope following their surprise defeat at Brighton and Hove Albion.
United boss Jose Mourinho has been the subject of much of the post-match scrutiny, yet Pochettino argued he is under the same amount of pressure as his opposite number.
"You do not believe that I am in the same position with the pressure?" Pochettino argued.
"We feel the same pressure every week. Of course, the circumstances during the year are different, but every game we are going to play is like you are under pressure.
"If you perform well, and you win the game, a fantastic week. But if you lose and not perform in the way that you expect, the pressure touches you, and we are always under pressure."
Three days to go...Old TraffordMon 27 Aug August 24, 2018
History is not on Tottenham's side as they have rotten record at Old Trafford in recent years.
Their only victories in their past 26 visits in the Premier League have come in 2012 and 2014, yet Pochettino has stressed his team must retain belief they can emerge victorious.
"We must believe because in football, if you don't believe, you lose before you arrive there," he added.
"We are confident of course, but we were confident in the last four years. But trust in yourself and in your team and believe that you can win always, that is the most important [thing].
"Then you can be focused on different aspects of the game. But the most important is the mentality and your confidence, and the way that you are going to approach the game."
