Apologies for being a bit of a buzzkiller...but joining/playing for the national team is fast becoming a bit of an anachronism. In case we have forgotten most if not all athletes performing at the Olympics in the "popular" sports (team or individual) are highly/very highly paid professional athletes. I am not referring to water polo or fencing of course and such there are great competing interests involved not least of which is the individual athlete concerned about his/hers ability to perform best for those who pay their salaries...or else.
The lure of national pride still exists of course and will continue for awhile as long as it is a once in 4 yr. commitment. But its more and more becoming an effort for personal gain I believe. A gold medal winning athlete gets a better paying endorsement than not. Sticking with basketball, joining/playing for the Canada basketball team is not just an olympic year commitment but joining the team for practices and playing qualifying games during each of the intervening years. Tough call for the players especially those who have a prominent role on their NBA team.
As an aside...following the soccer world cup, many an analyst has prognosticated that a big reason Messi did not have a particularly good tournament (at least by his standards) is that he was quite worn out...not just by the close marking by opposing teams but by the brutal schedule he had to endure in club and euro soccer prior to this tournament. Fiba of course milks its players and soccer leagues big time and then they have to play in the world cup. Refusal of course unacceptable.
One other point...check out the number of US players declining the invitation to join their national team this year. In previous years this would have been an anathema...refusing to play "for your country"? Traitor!