England's worst fears were confirmed on Thursday.
The Three Lions announced that right-back Trent Alexander-Arnold has been ruled out for six weeks with a thigh injury and will miss the Euro.
The 22-year-old Liverpool defender incurred the injury during the final stages of the England's 1-0 friendly win over Austria on Wednesday. Manager Gareth Southgate called the injury "not a good situation" after the match.
Southgate will not name a replacement for Alexander-Arnold until after his team's friendly against Romania on Sunday.
Right-backs Kyle Walker, Kieran Trippier and Reece James are already on England's roster.
Wednesday's match was Alexander-Arnold's 13th England cap.
The Three Lions open up their Euro campaign on June 13th in Group A action against 2018 World Cup semi-final opponents Croatia at Wembley.