Kevin Durant believes rivals of the United States will go into the Tokyo Olympics confident of producing an upset.

Winners of the last three Olympic gold medals, the USA are strong favourites to make it four in a row, with Australia and Spain seen as their closest challengers.

But Team USA have had a far-from-ideal Olympics preparation, defeated by Nigeria and Australia in exhibition games, though they did beat Spain in their final warm-up contest in Las Vegas.

They have lost significant players including having to make two late roster changes, adding JaVale McGee and Keldon Johnson to replace Kevin Love and Bradley Beal. 

Love withdrew with a calf injury, while Beal had to drop out due to health and safety protocols. 

USA face France in Saitama for their Group A opener on July 25 and Durant feels the favourites must be on guard.

"All of them [Olympic tournaments] are difficult," he said. "Every team wants to beat us, everybody wants to see us lose, so every game has a little bit more pressure to it. 

"A lot of guys dropped out, a lot of circumstances, and I'm sure other teams are seeing us lose and feel confident coming into the tournament.

"But we understand what we're getting ourselves into and we're looking forward to the challenge."

Durant feels like the team is starting to come together after those exhibition defeats.

The Brooklyn Nets forward added: "I feel like we're understanding what coach wants from us on both ends of the floor.

"Guys are getting more comfortable with each other and their roles on the team, and that's only going to bode well for us as we start to play real games. 

"So it was good to kind of get a punch in the mouth early on to remind us that it's not gonna be a cakewalk. 

"And so many people are used to Team USA coming in and blowing everybody out, so it was good for us to see that. Now, hopefully, those are the last losses."

After the conclusion of the NBA Finals, head coach Gregg Popovich is poised to welcome Devin Booker, Khris Middleton and Jrue Holiday to the set-up.

He is not sure how quickly the trio will adapt to new surroundings but is glad to have them en route.

"Well, there's not a whole lot you can do when they get here the day before," said Popovich.

"It's pretty obvious that they won't know everything that’s been going on, but luckily it's basketball. We'll try to keep it simple and just take care of what we think we can take care of.

"The good thing is they'll be in shape. I don't know how the plane's gonna affect them, that's not an easy flight. 

"It is true that they won't be as ready to play in the sense of execution that we might want, but that's understandable

"We are not sure [how we will incorporate them]. Something like that is pretty unique, there's no paradigm or game plan or rulebook.

"So it's something we'll discuss the rest of the week and just do what we think is best - it'll be an interesting situation for sure."

Popovich was asked if the players will have any film or play packages to review on the flight to Tokyo.

"They're gonna sleep," he replied.

In a further boost to the roster, USA guard Zach LaVine has cleared health and safety protocols so he will also travel to Tokyo and join up with the team.