LAS VEGAS -- The U.S. men's basketball team held its first practice Friday, and there was a quick reminder of the rocky run-up to the London Games.

Chris Paul was forced to leave the opening day of training camp to get an X-ray after hurting his thumb. The Americans don't believe the injury is serious, with USA Basketball chairman Jerry Colangelo calling it a tweak of a previous injury, and they hope Paul can practice Saturday.

That would be some rare good news for a team has been severely weakened by injuries. Dwight Howard, Derrick Rose, Dwyane Wade and Chris Bosh all were forced to pull out, leaving the Americans with 15 players vying for 12 spots. The roster will be announced Saturday night.

Colangelo said he would discuss the roster with the coaching staff on Friday night but would put off any judgments until after Saturday's practice.

"Tonight we'll have some deliberations about what took place today, but we're still not making the final decision until we practice tomorrow," he said. "We told the players we were going to do that and we're not going to change."

LeBron James, about two weeks removed from winning NBA Finals MVP honors after Miami's championship, didn't scrimmage Friday so he could get some extra rest. Deron Williams sat out as planned because he still can't sign his $98 million extension with the Nets, and top draft pick Anthony Davis remained sidelined because of a sprained ankle.

That allowed the Americans time for extra looks at some of the players on the bubble, such as Rudy Gay, Eric Gordon, James Harden and Andre Iguodala.

"You could build a case for each of the contenders if you will, depending on what you want," Colangelo said. "It's like a menu: Another shooter, it's Eric Gordon. You want a scoring guard, it's Harden. You want a defensive specialist, it's Iguodala. You want another guy with length who can shoot the ball and run the court, it's Rudy Gay."

What the Americans really want is another big body, having lost their 2008 center rotation with the absences of Howard and Bosh. James and Carmelo Anthony even could see time at center, which would create offensive mismatches for the Americans but would leave them undersized on defense.

The need for size has Colangelo intrigued by Davis, the shot-blocking college player of the year who led Kentucky to the national title. But he's not ready to go full speed yet after hurting himself less than a week ago while working out with the Hornets, leaving him frustrated but eager.

"Anxious to get on the court, be healthy again, show the coaches my full abilities," Davis said.

Colangelo said it would be a "reach" to pick Davis without really seeing him, but acknowledges the 6-foot-10 forward has qualities no other U.S. player has. So he could pick him Saturday and hope he's ready in a couple of weeks, with the Olympic opener not for another three weeks.

This being Vegas, is Colangelo a gambler?

"I've been known to be that, but I'm saying that, I'm one voice in the wilderness maybe," Colangelo said. "We'll find out tonight."

Gay played with the Americans on their gold medal-winning team in the 2010 world basketball championship and is versatile enough to play each frontcourt position. His chances of making the roster may have improved with all the other losses at the forward spots.

"Just basically going out there, showcasing what I can do," the Memphis forward said. "If they like it, they don't, I'll find other ways to get better and then compete next time."

Gordon was considered on the cut line in 2010 and ended up becoming a key contributor for the Americans, and believes he can do it again, even at a crowded guard spot.

It's easier for the guys with size, which is why Knicks center Tyson Chandler knows he'll be on the team. The Americans insist they are deep enough to overcome their losses, and he said just looking at the practice floor shows why.

"You look to your left and your right, and the names and level of athletic ability and skill is off the chart," he said.

The Americans will train on the campus of UNLV through next Wednesday before closing this portion of their camp with an exhibition game against the Dominican Republic on Thursday.