There is no news regarding the seriousness of the injury. Still two weeks to go for the tournament, and there is a chance that Kostas Sloukas might still play in the world cup. Their first match is against Montenegro is on September 1. If he is not playing, then there will be a lot more additional pressure on other players such as Giannis Antetokounmpo.
BTW, anyone watched the warmup match between the United States and Spain? The American played really well, although they were without the star players who are still with the NBA teams. Donovan Mitchell and Khris Middleton were impressive and Spain went down by a good margin. The next warmup match for the US is against Australia.