Belgium caoch Marc Wilmots said Friday that defender and captain Vincent Kompany may not be available for Tuesday's game with the United States due to a recurring groin issue.
Kompany did not play in the team's final Group H match against South Korea after aggravating the injury.
According to the Associated Press, Wilmots said that it was "impossible to say now" whether Kompany would be able to go, and that he considered the Manchester City star his "right-hand man" on the field.
Belgium is already dealing with a host of injuries on its back line. This would just add to the troubles since Thomas Vermaelen, Laurent Ciman, and Anthony Vanden-Borre are dealing with injury issues of their own.
In three matches in the group stage, Belgium only surrendered a single goal. The absence of Kompany, however, would certainly be a hit.