Christian Pulisic was substituted at half-time after scoring the winning goal for the United States against Iran in their Group B match.
Pulisic was involved in a hard collision with Iran keeper Alireza Beiranvand shortly before half-time as he tapped in a headed cross from Sergino Dest to put the US up 1-0.
Brenden Aaronson came on for Pulisic after half-time.
The early reports indicate Pulisic suffered an abdominal injury.
Via ESPN