It only gets tougher from here on out.

The United States has been challenged in its last three games of group play at the Rio Olympics. After beating Australia by 10, it only beat Serbia and France by three points in each of those wins. Team USA still finished group play undefeated and the top seed as we head to the knockout stage.

The next opponent for the Americans will be Argentina, the last country besides the U.S. to win a gold medal at the Olympics. That was back in 2004 and somewhat unfortunate for Argentina, its team this year features most of those same players. Much older now, Argentina managed just the fourth seed from its group thanks to losses to Lithuania and Spain.

Team USA hasn't looked its normal dominant self as of late. Some critics have pointed to a lack of focus, while others realize the makeup of the team isn't the normal juggernaut we saw in the 2008 and 2012 Olympics.

The United States played Argentina in an exhibition game back in July in Las Vegas and had absolutely no trouble winning. Team USA rolled to a 111-74 win behind 23 points from Kevin Durant, 18 from Paul George, and 17 from Carmelo Anthony. The 22 offensive rebounds for the U.S. was another reason for the big win.

Other countries are notorious for not showing their best stuff in exhibitions so that result needs to be take with a grain of salt. Either way, the United States will still be heavy favorites.

Argentina has been led in Rio by Facundo Campazzo‘s 16.4 points per game. Andres Nocioni (15.6), Manu Ginobili (15.2) and Luis Scola (14.8) make up most of the other reliable scoring options.

Argentina has experience and a chance to push the U.S. as much as any other country. Still, if Team USA loses it will be considered a mighty letdown. The game tips off tomorrow tonight at 5:45 p.m. EST.