Slovakia goalkeeper Martin Dubravka could miss the Euro 2020 play-off semi-final with the Republic of Ireland through injury.
The 31-year-old is expected to be sidelined for several weeks by a heel problem, with reports it could be mid to late October before he returns.
He will definitely sit out his country's Nations League fixtures against the Czech Republic and Israel next month.
The semi-final with Stephen Kenny's side is 8 October, meaning the goalkeeper will need to recover promptly to make the game.
Dubravka is seen as one of the leading players for the Slovaks and is also a key player for Newcastle United.
A statement on their official website said: "Newcastle United goalkeeper Martin Dubravka will miss the start of the 2020/21 Premier League season after suffering a heel injury.
"The 31-year-old is likely to be sidelined for several weeks, meaning he will also miss Slovakia's UEFA Nations League fixtures against Czech Republic and Israel next month.
"Dubravka has not missed a Premier League game since making his debut in a 1-0 win against Manchester United in February 2018 and won the club's Player of the Season award for 2019/20."
The news will also come as a huge blow to Newcastle United head coach Steve Bruce who, like predecessor Rafael Benitez, has come to rely upon the dependable Dubravka.
He will now have to turn to Karl Darlow, who has served as Dubravka's deputy in recent times, or summer signing Mark Gillespie with England Under-21 keeper Freddie Woodman having joined Swansea on loan for the season after signing a new contract at St James' Park.