Blake Griffin has withdrawn from playing for the U.S. national basketball team this summer. The Kobe 9 Chaussures Angeles Clippers star was one of 19 players selected to the roster from which the World Cup Nike Hyperdunk 2014 will be chosen. Griffin said Thursday that he wants to dedicate all his energy to improving and preparing for the upcoming season. Griffin joins Oklahoma City guard Russell Westbrook in not participating. Westbrook dropped out to rest previous knee injuries. The Americans begin training camp Monday in Las Vegas, a month before the World Cup of Basketball opens in Spain.