Mason Greenwood and Phil Foden were dropped from Gareth Southgate's England squad after the pair breached quarantine rules by inviting women to their hotel rooms in Iceland.
Both players were omitted from the side for Tuesday's Nations League clash with Denmark after welcoming women to their hotel rooms in Reykjavik on Sunday, according to ESPN UK's James Olley.
"Unfortunately this morning, it was brought to my attention that two of the boys have broken the COVID-19 guidelines, in terms of our secure bubble," Southgate told reporters Monday, according to Mantej Mann of BBC Sport.
Greenwood and Foden will now fly back to England after violating Iceland's strict isolation rules amid the coronavirus pandemic.
"So we had to decide very quickly that they couldn't have any interaction with the rest of the team and wouldn't be able to train," Southgate added. "Given the procedures we have to follow now they will have to travel back to England separately.
"Nothing has happened in the areas we occupy in the hotel. We are still getting to the depths of all the information because this was only brought to my attention a couple of hours before training, so I'm still getting to grips with the detail."
The English Football Association (FA) is expected to investigate the allegations against Greenwood and Foden, according to Simon Stone of BBC Sport.
"What is clear is there is a breach of the COVID-19 guidelines. The whole squad have really followed that to the letter. I'm not going into any more details until I'm aware of everything," Southgate added.
Manchester United's Greenwood, 18, and Manchester City's Foden, 20, both made their international debuts during Saturday's narrow victory over Iceland.
England currently sit second in Nations League Group A2 on three points after one match played, just behind Belgium on goal difference after Roberto Martinez's Red Devils topped Denmark 2-0 on the weekend.
