England's Ben Chilwell and Mason Mount have to self-isolate as a precaution after coming into close contact with Scotland's Billy Gilmour and could miss Tuesday's game with the Czech Republic.
Gilmour has since tested positive for Covid-19 and will miss Scotland's final group game against Croatia on Tuesday.
"I can't say it isn't disruptive," said England boss Gareth Southgate.
Asked whether the pair would be available for Tuesday's game, Southgate added: "We don't know at the moment.
"There's obviously got to be quite a doubt but there's still a lot of discussions and investigations going on behind the scenes, so at the moment they're isolating and we just have to find out over the last 12 hours or so.