Ryan Fraser is set to pull out of Scotland's squad for their Euro 2020 play-off final with Serbia next week due to a hamstring injury.
The winger was not included in Newcastle's squad to face Southampton in the Premier League on Friday night.
Fraser now appears likely to miss the game - live on Sky Sports Football - that could see Scotland qualify for their first major tournament since the World Cup in France in 1998.
The 26-year-old scored the only goal in Scotland's 1-0 Nations League victory against the Czech Republic at Hampden last month. Steve Clarke's side have further Nations League fixtures against Slovakia (November 15) and Israel (November 18) this month.
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Fraser has made 14 appearances and scored two goals for Scotland since making his debut in June 2017.
UEFA says it has no plans yet to change the format of Euro 2020 amid reports it is considering moving next summer's tournament to Russia.
European football's governing body decided in March to postpone the tournament by 12 months due to the coronavirus pandemic, but has so far stood by the 12-city format it had originally devised.
French newspaper Le Parisien reported earlier this week that installing Russia, which hosted the World Cup in 2018, as sole host for the finals was one option being considered by UEFA, with infection rates rising again across the continent.
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While UEFA has not ruled out changing the format, it said in a statement that it currently had no plans to do so.
"UEFA intends to hold Euro 2020 in the format and the venues confirmed earlier this year and we are working closely with all host cities on preparations," the statement read.
"Given the uncertainties surrounding Covid - over which neither UEFA nor the local organising bodies have control - it is currently too early to say whether those games in June and July will have restrictions either on fans or even their staging."