PORTUGAL are back in international action after lifting the first ever Nations League trophy in the summer.
A Goncalo Guedes strike fired Cristiano Ronaldo and co past Holland in the final, yet their Euro 2020 place remains far from secure.
The Portuguese started off with draws against the Serbs and Ukraine, with their only wins coming against Luxembourg and Lithuania.
Serbia are in equal need of a win after a 5-0 thumping in Ukaine led to the sacking of former boss Mladen Krstajic.
THIS Euro 2020 qualifier is set for Saturday, September 7.
Kick-off is at 7.45pm.
It will be held at the Stadion Rajko Mitic in Belgrade.
EVERY match of Euro qualifying is being shown exclusively live on Sky Sports.
This clash is available on Sky Sports Premier League, with coverage starting at 7.30pm.
If you're a Sky customer, live streaming is easy - just download the Sky Go app on your mobile, tablet, games console or PC.
Whilst non-subscribers can purchase a .
In Serbia, the match will be live on Nova S and Sport Klub while RTP and SportTV are the Portuguese broadcasters.
Serbia XI: Dmitrovic, Maksimovic, Milenkovic, Nastasic, Kolarov, Matic, Milivojevic, Lazovic, Kostic, Tadic, Mitrovic
Portugal XI: Rui Patricio; Nelson Semedo, Ruben Dias, Jose Fonte, Guerreiro; Danilo, William Carvalho, Bruno Fernandes; Bernardo Silva, Gonçalo Guedes, Cristiano Ronaldo