Phil Foden and Mason Greenwood are to leave the England camp after breaking coronavirus quarantine guidelines in Iceland, says manager Gareth Southgate.
The Football Association is investigating the breaches after Saturday's 1-0 Nations League victory.
Manchester City midfielder Foden, 20, and Manchester United forward Greenwood, 18, both made their senior international debuts in the game.
Southgate described the pair as "naive" and said they have apologised.
"Two of the boys have broken the Covid-19 guidelines, in terms of our secure bubble," Southgate said on Monday.
"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.
"Obviously they have been naive. We have dealt with it appropriately. I recognise their age but the whole world is dealing with this pandemic.
"Now they will have to travel back to England separately.
"Nothing has happened in the areas we occupy in the hotel."
Greenwood's England call-up followed a breakout season at United, in which he scored 17 goals, while Foden became a regular starter in Pep Guardiola's City side in 2019-20.
A Manchester City spokesman said Foden's behaviour was "totally inappropriate" and "fell well below the standard expected of a Manchester City player and England international".
A Manchester United statement said the club are "liaising with the Football Association and are disappointed with the actions of Mason Greenwood".
England face Denmark in the Nations League on Tuesday (19:45 BST kick-off).