England manager Thomas Tuchel has revealed that Declan Rice spent much of the three days leading up to the Three Lions' World Cup quarter-final against Norway confined to bed with illness.
Despite his condition, Rice was named in the starting line-up for England's dramatic 2-1 victory in Miami.
However, the Arsenal midfielder appeared to struggle in the intense heat and was replaced at half-time by club team-mate Eberechi Eze.
England found themselves behind after Andreas Schjelderup put Norway ahead, but Jude Bellingham equalised just before the break before scoring the decisive goal in extra time to send the Three Lions into the semi-finals.
England will now face Argentina, who progressed by defeating Switzerland, with the semi-final taking place on Wednesday, 15 July at 20:00 BST.
Tuchel explained that several players found the humid conditions difficult to cope with.
"We had some players struggling in the heat," he said.
"Ezri Konsa was one of them with cramps and issues in his hamstrings."
The England boss added that Rice's substitution had been planned regardless of the scoreline.
"We decided at half-time to become more offensive," Tuchel said.
"I made that decision when we were 1-0 down and didn't want to change it after we equalised."
Rice had already been managing a nerve problem affecting his hamstring and lower back before illness further hampered his preparations.
Although he trained on the eve of the match, Tuchel knew the midfielder would not be able to complete the full game.
"We had to take either Elliot [Anderson] or Declan off," Tuchel explained.
"Knowing Declan had spent most of the previous three days in bed, I knew he couldn't last 90 minutes."
"With the possibility of the game going to 120 minutes, I didn't want to use another substitution later because of fatigue."
"That's why we took him off earlier than we otherwise might have."
Rice, who helped Arsenal secure the Premier League title last season, has started five of England's six matches at the 2026 World Cup, missing only the group-stage victory over Panama.
