Many other NBA players are playing. #5 overall pick Jonas Valanciunas is playing, and his team played the Czech Republic (Vesely's home country today, and Lithuania beat them 92-77. I think the Czech's would've been glad to have Vesely's help.
Even Seraphin is playing for France. This might have been explained before, and I might have just not seen it, but can somebody tell me why Vesely isn't playing? I think it would be good for him to get some basketball run against good competition, especially because of the lockout and no Summer League