Portugal head into their Euro 2016 qualifier with Serbia knowing that a victory would go a long way to securing a top-two spot.
Fernando Santos's men have six points from three games, results which leave them in second place behind Denmark, but a win on Sunday night would take them eight points clear of their opponents.
Serbia's campaign has been hindered after they were deducted three points for crowd trouble against Albania, and a setback in Lisbon would leave the team targeting a playoff spot.
Portugal go into the fixture in Lisbon after securing a 1-0 win in Argentina in their last match, but Santos could make changes to the team that started that contest.
Rui Patricio is expected to return in goal, while duo Fabio Coentrao and William Carvalho could line up in defence and midfield respectively.
Star man Cristiano Ronaldo will be searching for his 53rd goal for his country after an indifferent spell in club colours for Real Madrid.
Serbia coach Radovan Curcic may name Manchester City defender Aleksandar Kolarov and on-loan Filip Duricic in his side after both failed to start in the friendly in Greece in November.
Portugal:
Form in Euro 2016 qualifying: LWW
Form in all competitions: WLLWWW
Possible starting lineup: Rui Patricio, Pepe, Bruno Alves, Jose Bosingwa, Coentrao, Tiago, Nani, Danny, Joao Moutinho, William Carvalho, Cristiano Ronaldo
Serbia:
Form in Euro 2016 qualifying: DWL
Form in all competitions: LDDWLW
Possible starting lineup: Stojkovic, Tosic, Ivanovic, Tomovic, Kolarov, Matic, Tosic, Petrovic, Duricic, Markovic, Mitrovic
Sports Mole says: 2-1
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