Portugal centre-back Pepe was unable to take part in the Portuguese national side's first training session ahead of their Euro 2016 qualifier against Serbia, being restricted to working out in the gym.

According to reports in Portugal, the Brazil-born Real Madrid stopper was the only member of the 24-man squad who didn't take to the pitch on Tuesday, having been subbed off in this past Sunday's 'Clásico' in the 73rd minute after picking up a knock.

The 32-year-old's club and international teammate Cristiano Ronaldo, who played all 90 minutes at the Camp Nou and scored Real Madrid's equaliser, was able to train without any problems.

Pepe's problem isn't believed to be anything major, though, and he remains odds-on to feature in the starting line-up for the Serbia encounter, as he is a key figure in the Portuguese set-up.

Portugal will be deprived of their coach, Fernando Santos, in the dugout for this Sunday's game, as the tactician will be sitting out the first of two matches he has been suspended for in relation to an offence committed at the World Cup, when he was in charge of Greece.