England pair Mason Mount and Ben Chilwell are likely to be isolating because of a judgement call over what constitutes close contact, a coronavirus test specialist has said.

Mount and Chilwell will miss England’s final Euro 2020 group match against the Czech Republic on Tuesday and quarantine until next Monday after being identified as close contacts of Scotland’s Billy Gilmour.

Scotland midfielder Gilmour, it emerged on Monday, has tested positive for Covid-19.

The three players are all team-mates at Chelsea and were seen talking together after the goalless draw between the two countries at Wembley last Friday.

It is believed their conversation continued after the players left the field and headed down the tunnel, and it is there that problems are understood to have arisen.

The fact that no Scotland players have been identified as close contacts of Gilmour in addition to the England pair has raised eyebrows but, with no hard definition of what close contact is, reasoned decisions have to be made by authorities involved.

News of their isolation was communicated by the Football Association following consultation with Public Health England.

“It comes down to interpretation,” said immunologist Denis Kinane, the co-founder of Cignpost Diagnostics, a Government-accredited service offering Covid screening and testing.

“Nobody actually knows for definite and a lot of people use the public health definition to make rules.

“They’ll have tracked back a bit and seen there were two English players in close contact with him in terms of hugging or chatting.

“Essentially what we’re talking about is spit. Any saliva or aerosols in the air – kissing, laughing, singing, coughing, that kind of thing can spread it.

“When we talk about what constitutes close contact, there is a time element to it, an activity element to it and then the distance between the people.”

Kinane says it is possible other elements were taken into consideration when it was decided how long the players should isolate for.

He told the PA news agency: “If they’ve been asked to isolate until Monday they must think there was some significant contact, or they are making an example of them, or falling back on public health rulings and doing everything by the book.

“But we just don’t know and we don’t have all the facts.”