US National Basketball Association stars are concerned that playing in international events is hurting their ability to play their best in quest of a league crown, US media reported.

ESPN's Ric Bucher said that many players and coaches have expressed private reservations about US stars playing in events such as the World Championship in Japan last year and August's Americas qualifier for the 2008 Beijing Olympics.

Elton Brand, a power forward for the Los Angeles Clippers, told ESPN that he would need to see where his body condition was after the season before knowing if he could complete his three-year commitment to the US team.

Many top US players agreed to be available for three years to play in the world championships, Olympic qualifying and next year's Beijing Games, where ESPN reported that Dwyane Wade and LeBron James could make 500,000 dollars each simply from shoe endorsement contract provisions simply for playing.

That agreement came in the wake of a disappointing third-place US finish at the 2004 Athens Olympics and has given USA Basketball a pool of talent to field top teams as needed without an excessive load on those unwilling to bear it.

But the ESPNEWS report noted that James, suffering a big toe injury, and Wade, who has missed time for reigning NBA champion Miami, are among more than half the players from the US world team who have been hurt or struggled in this NBA season.

While having US talent in international events is a huge marketing boost for the NBA, the compromise of mental and physical wear and tear could contribute to similar woes as football club teams have with World Cup and UEFA campaigns.