The Arsenal player has failed to recover from a hamstring strain that he picked up during Belgium's 1-0 win over Russia in Group H.
Coach Marc Wilmots told reporters: "For Thomas the game against the USA is just too early. When we reach the quarter-finals, the chances are very good that he gets fit by then. Within two to three days, he can resume group training sessions in principle."
Meanwhile, Vincent Kompany remains a doubt for the encounter in Salvador due to abdominal and groin pain.