Tottenham striker Harry Kane has been sent for a scan on his ankle.
The England skipper was in hospital last night for a precautionary scan after suffering the knock in England's 6-2 win over Iran on Monday.
Kane is now a major doubt for Friday's second group stage clash against United States, says The Sun.
The Spurs forward was still feeling discomfort on Tuesday and boss Gareth Southgate insisted on tests in Doha.
England are still hopeful that it is not too serious as he took part in a private warm-down session.
But the loss of Kane on Friday would be a huge blow for England despite their encouraging start.