LAS VEGAS -- Dwyane Wade slumped in a chair, bags of ice resting on both knees and his right wrist.

The U.S. basketball team returned to training camp Monday night after nearly a week off. And with games coming soon, it looks like this session is going to be a little more serious.

"We had a great practice, really hard," U.S. coach Mike Krzyzewski said. "Really hard."

Before Krzyzewski put them through a long workout at UNLV, the 15 returning players were first treated to a speech at their hotel from Sen. John McCain, giving the team an emotional boost before they took the floor.

"It was amazing. It was tremendous what Sen. McCain did," Krzyzewski said. "He talked about his service to our country, which I don't think we'll be able to replicate. He's supporting us, and he knew every guy's name. And our guys really appreciated that."

While Krzyzewski used the first session of camp to get to know his roster of NBA players, the Duke coach planned to focus more on the basketball aspects this time.

And before he even got to the arena, he knew his players were ready to jump back into things.

"I saw it as soon as I checked into the hotel today," Krzyzewski said. "I ran into a few of them, and there's a smile on their face. I said, 'You read to go'? They said, 'Coach, we're excited.' And they did that same thing when they came on the court today. They worked hard."

The start of the world championships are only 20 days away, and their first exhibition game comes Thursday night against Puerto Rico -- the same team that embarrassed them in their opening game at the 2004 Olympics.

The more focused mentality was evident during a lively scrimmage late in Monday's practice. Shortly after LeBron James went hard to the basket to draw a foul from Carmelo Anthony, Anthony responded with a clean steal of James and went in for a layup.

"In here, when you score it means a lot," Wade said about the level of competition. "You're doing it in here, and guys are scoring, then you know you're doing a good job."

The U.S. team reconvened without Adam Morrison, Luke Ridnour and Shawn Marion, who didn't make the 15-man roster that will travel to China and Korea for more training and exhibition games following this camp. Marion would undoubtedly have been a part of that group, but he developed a sore knee during the first segment.

Three more players will have to be dropped before the Americans submit their final 12-man roster before the start of the worlds.

Also expected during this part of camp was a visit from another injured teammate: Kobe Bryant. The NBA's leading scorer, one of the first players chosen by managing director Jerry Colangelo for the national team, is unavailable while rehabbing from knee surgery earlier this month. However, USA Basketball previously said that Bryant was still expected to join his teammates in Las Vegas and travel with them to Asia.

Bryant is expected to arrive in time to watch Tuesday's scrimmage against Puerto Rico.

And he'll no doubt see more spirited action from his teammates, especially on the defensive end. Krzyzewski is dedicated to playing a pressure-style system on that end -- and the players seem to be grasping it.

"The guys have not been conditioned to play this way in the NBA," assistant coach Nate McMillan said. "The style he wants to play, up in your chest every possession. Everybody is up pressuring the ball.

"We feel we're very athletic. We're going to be more athletic than any team that we go up against and we should be deeper than any team we go up against. We want to use that to our advantage."