John Stones, an England defender, has resumed training following his convalescence.
To stop the illness from infecting his teammates, he stayed alone in his hotel room on Wednesday.
against Sunday, England takes against Serbia in Gelsenkirchen, Germany, to begin their Euro 2024 campaign.
Although Stones played 45 minutes in England’s final warm-up loss to Iceland on Friday, he has only completed 90 minutes in the last two months.
During the last three major championships, he has been an important player for England.
Due to a calf injury, Stones’ habitual central defence partner Harry Maguire will be out from the competition.
In their two Group C matches, England takes on Slovenia on June 25 and Denmark on June 20.