LAS VEGAS (FIBA Basketball World Cup) - John Wall couldn't believe his name didn't appear on the USA Basketball national squad roster for 2014-16 that was announced earlier this year.

The Washington Wizards playmaker, an Eastern Conference All-Star in 2013-14, spoke of his disappointment yet didn't complain.

Instead, the guard began to play some of the best basketball of his career and helped the Wizards not only reach the playoffs but win post-season games.

The strong performances put him in contention for a late call-up and this week USA Basketball have reportedly added the determined Wall to their training camp roster in Las Vegas.

He becomes the third player not originally named in this summer's USA Basketball training camp squad to earn a camp invite.

DeMar DeRozan of the Toronto Raptors and Chandler Parsons of the Dallas Mavericks were added to the USA Basketball Pool for 2014-16 on 14 July and will also be in Las Vegas.

Wall's arrival to the USA set-up coincides with the unexpected withdrawal of Los Angeles Clippers forward Blake Griffin.

"I'm disappointed he's not going to be with us," USA Basketball President and national team managing director Jerry Colangelo said to USA Today.

"It's unfortunate (because) it's been two competitions in a row (that Griffin has missed), but it sounds like a broken record because it happened recently with someone else."

Another big man that USA Basketball had hoped to add to their squad, Portland Trail Blazers center LaMarcus Aldridge, also made himself unavailable this month.

The Americans are nevertheless going to be stacked with talent and among the favorites to reach the top of the podium, something they did in 2010 with an entirely different squad to the one that captured the Olympic title in 2008.

Colangelo isn't fretting over the absences of Griffin and Aldridge.

"There's a reason for having a national team roster, and having a list of talented athletes who are on the national team roster, because there are so many variables," he said.

"It just opens up an opportunity for somebody else. I'm very open minded, so it could be someone who comes in from the (Team USA) Select Team.

"Who knows? We want to present the best team we possibly can. But there's no additional player from outside this group that we're going to add at this point."

The Select Team will assemble in Las Vegas and train with the USA National Team 28-31 July.

It consists of: Harrison Barnes (Golden State Warriors), Trey Burke (Utah Jazz), Jimmy Butler (Chicago Bulls),  Draymond Green (Golden State Warriors), Tim Hardaway Jr (New York Knicks), Tobias Harris (Orlando Magic), Doug McDermott (Chicago Bulls), Victor Oladipo (Orlando Magic), Mason Plumlee (Brooklyn Nets), Miles Plumlee (Phoenix Suns), Marcus Smart (Boston Celtics), Dion Waiters (Cleveland Cavaliers), and Cody Zeller (Charlotte Hornets).

"USA Basketball's select teams are critical for getting some of the game's brightest and most promising young players experience at the USA National Team level, and getting them into our pipeline," Colangelo said in a USA Basketball statement.

"Again this summer, as was done in 2007, 2008, 2010 and 2012, the members of the USA Select Team will play an important role in helping prepare the USA national team for the 2014 FIBA World Cup.

"Being chosen for the Select Team is an honor and an important step in becoming involved in USA Basketball's national team program in the future."

"Kevin Durant, Kyrie Irving, Kevin Love, Derrick Rose, Russell Westbrook and many other terrific players got their USA national team start through the select team."

FIBA