While it's unclear where Wembanyama's clot is located in the shoulder, deep vein thrombosis (DVT) occurs when a blood clot (thrombus) forms in one or more of the deep veins in the body:

Wembanyama's clot was discovered, according to The Athletic's Sam Amick, because Wembanyama had experienced low energy throughout All-Star Weekend and the days that followed. Blood clots are rare in the NBA, but they do happen, and the outcomes for players who get them can vary wildly.

All-Star Victor Wembanyama won’t be able to finish the rest of the NBA season due to deep vein thrombosis. What is this dangerous condition?