Portugal manager Roberto Martinez is facing a crisis at centre-back ahead of their UEFA Nations League clash with Poland in Porto on Friday night.

Manchester City's Ruben Dias, and young Sporting Lisbon centre-back Goncalo Inacio are both out injured, leaving Antonio Silva as the only recognised player in that position with any international experience in the squad.

However, Martinez's problem is enhanced by the fact Silva has not been a regular in the Benfica side of late, playing in just two of their last six matches.

Based on form, uncapped pair Tomas Araujo and Tiago Djalo would be the preferred option, but Martinez may be unwilling to throw two inexperienced players in at the same time in such an important position, so the former could be paired with his Benfica teammate Silva here.

Further forward, injuries are mounting in midfield too, where Ruben Neves, Matheus Nunes and Pedro Goncalves are all absent, while Diogo Jota and Goncalo Ramos are also recovering from injury in attack.

That means that there is little question that Cristiano Ronaldo will lead the side out and start up front once more, winning his 217th cap in the process.

Either side of Ronaldo, Pedro Neto and Rafael Leao should be confident of getting the nod given their impressive club form over the past month.

Neto has had to work hard to break into a Chelsea team loaded with competition, while Leao's performance away to Real Madrid in particular was one of the finest by any wide player in the Champions League so far.

Raphael Guerreiro remains out of favour having not received a call up in over a year, so at left-back, Nuno Mendes's competition will come from Lazio's Nuno Tavares, who has been one of the surprise breakout stars of the Serie A season so far, and has won his first call up.

Portugal possible starting lineup: Diogo Costa; Dalot, Antonio Silva, Araujo, Nuno Mendes; Bruno Fernandes, Joao Neves, Bernardo; Neto, Ronaldo, Leao