Luka Milivojevic has tested positive for coronavirus and will miss Serbia's Euro 2020 play-off final with Scotland on Thursday night.
The Crystal Palace captain tested positive on Monday and also tested positive in a follow-up test on Tuesday and is self-isolating in Serbia.
He is the third Serbian player to test positive for coronavirus in the build-up after West Brom defender Branislav Ivanovic and Sassuolo's Filip Djuricic tested positive.
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The rest of the Serbia squad tested negative and are clear to face Scotland at the Red Star Stadium in Belgrade for a place at next summer's delayed-Euro 2020.
A Serbian FA statement read: "After regular testing on COVID-19, performed on Monday upon the arrival of representative team players to the Sports Center of the Serbian FA in Stara Pazova the result for captain of Crystal Palace Milivojević came up positive.
"In accordance with UEFA medical regulations and protocols, Luka Milivojević left the sports center immediately after receiving the result and remained in Serbia in self-isolation at home.
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"The day after he has undergone another control test, which also came up positive. He will stay in Serbia in accordance with current laws of the Republic of Serbia related with the COVID-19 pandemic.
"All the players and technical staff members of the A team had negative results after additional testing, hence all the other representative players are available to the coach Ljubiša Tumbaković for tonight's game vs. Scotland."
It has been a disruptive week for Serbia as they prepare to face Steve Clarke's side. There were doubts whether Serbia's Italy-based players would be allowed to join up with the squad.
Aleksandar Kolarov (Inter Milan), Sergej Milinkovic-Savic (Lazio), Nikola Milenkovic and Dusan Vlahovic (both Fiorentina) all managed to travel.
Djuricic and Werder Bremen's Milos Veljkovic miss out.
It's undoubtedly the biggest game in a generation and the prospect of Scotland finally making it to a major European finals is within reach.
But just what are our chances against Serbia in Belgrade on Thursday night in the Euro 2020 play-off final?
Like us, Serbia have a history of failing in big games but they are favourites for this one given their excellent performance in seeing off Norway in Oslo 2-1 after extra time in their Nations League semi-final win with goals from the hugely talented Sergej Milinkovic-Savic of Lazio.
As well as Aleksandar Mitrovic of Fulham, Serbia have plenty of talented players plying their trade all over Europe - Italy in particular - and there has been some confusion over Covid-19 related issues with doubts surrounding a number of players.
All of us in Scotland recognise that Serbia have players playing for Inter Milan, Fiorentina, Lazio and Torino but we should not underestimate the quality in our squad. When Steve Clarke can call upon players from Liverpool, Manchester Utd, Arsenal and Aston Villa as well as a couple from Celtic and Rangers, then no wonder he can be confident of a good performance.
Admittedly, the 120 minutes we needed to get past Israel at Hampden in our semi-final was turgid and uninspiring but we made it thanks to all five nominated players scoring pressure penalties and as Clarke keeps telling us, we are now unbeaten in eight internationals.
All being well, we should have a strong starting XI.