RIO DE JANEIRO (Rio 2016 Olympic Games) - If anyone in the USA team had wondered about the sort of Olympic competition that might be awaiting them in Rio de Janeiro, they might have asked Carmelo Anthony.

While Anthony has won gold medals with the USA in Beijing and London, he's also acutely aware of the potential dangers. He is the only player in this year's side to have tasted defeat with the national team. It was something he did three times at the 2004 Olympics and once more at the 2006 FIBA Basketball World Cup.

Anthony looks on as Greece celebrate after defeating the USA 101-95 in the Semi-Finals of the 2006 FIBA Basketball World Cup

Anthony and Kevin Durant would have known that despite the Americans' unbeaten run since their 101-95 defeat to Greece in the Semi-Finals of the World Cup 10 years ago, there have been scares.

Spain pushed the Americans hard in the Beijing 2008 Olympic Final that Anthony played in and Durant was in the 2010 FIBA Basketball World Cup squad that almost went to overtime with Brazil. Both played in the Olympic Final of 2012 against Spain, a game that was even closer than the title game four years earlier.

There were USA blowout wins in all of those tournaments, but also warnings that if they are not turning on all cylinders and the opponents are, then an American side, no matter how talented, can be upset.

Paul George has admitted after hard-fought wins over Australia, Serbia and France, however, that the competition is tougher than he'd anticipated.

In remarks to the American media, George admitted: "I think to start out, personally, I thought we were going to dominate and these games were going to be easy."

It didn't help George and other newcomers to the USA roster that they warmed up for the Olympics with games against China and Venezuela. China did not win a game in Rio and they were the only side that Venezuela managed to defeat.

The USA played friendlies against both Argentina and Nigeria but did so, it seems, before those teams had hit their stride. Argentina have reached the Quarter-Finals and will play the USA on Wednesday while Nigeria upset Croatia and played well against Spain and Lithuania but did not advance.

"We started playing better competition," George said. "I think you see, across the board, these teams are pretty good. The luxury they have is they've been together for so long.

"You really can't stress that enough. You see it. They just read each other so well. I think that’s the biggest thing that really separates us from them."

The USA now have five Olympic games under their belt and also the luxury of having had their last game on Saturday, which afforded them a little more rest and a chance to size up the competition.

DeMarcus Cousins played on the USA team that thoroughly dominated the 2014 FIBA Basketball World Cup.

If anyone should be surprised that the Americans have had to grind out a few victories, it should be him because no one trouble the Sacramento Kings star in Spain. France were a handful for the Americans, though.

"They play aggressive," Cousins said. "They execute extremely well, and that's a team that's been playing together for a while. They're experienced professionally and in their national team. When you have them two things into one, it makes it tough."

Either France or Spain, another experienced side with plenty of talent, will be the Americans' opponents in the Semi-Finals if they beat Argentina.

FIBA