The details are still sketchy but the Suns organization has confirmed to me they are talking with the Slovenian team doctors today and that initial reports are that the injury is not serious.
The best report we can find online is from a Slovenian media source:
Young Slovenian players Goran Dragić (23), which is the brilliant performances in the European Championship once again confirmed the quality of his playing, due to a knee injury lateral ties rested at least 4 days. At extremely important game against Lithuania at striking the knee to the tension side was a knee-links (Stage I), which means that it will be releasing the next two games in Group F. Goran Dragić will perform in the coming days intensive therapy.
My translation of that google translation is that he injured his knee ligaments which will require him to rest 4 days and that he will receive treatment. That sounds like a sprain or strain to me but until we hear more from the Suns we won't know for sure.
Dragic is averaging 22 minutes, 9.3 points, 1.3 assist, 2.3 rebounds and 2 steals over the four games he's played in the tournament. He missed the team's game yesterday, a Slovenian win over host country Poland.
The Slovenian team is already without NBA players Beno Udrih and Sasha Vujacic who also have knee injuries. Despite missing those players, Slovenia has the second best record (4-1) in the tournament behind undefeated Turkey. The top two teams play later today.
h/t to Bright Side of the Sun reader Oren (from Israel) for being on top of this story