Left back is traditionally a position that not many Portuguese players excel at. Guerreiro is young lad. He looked good against Armenia. But the natural back-up is Antunes IMO. Not world class, but solid.
Tiago and Carvalho played very well. Clearly on another level. Bosingwa skills have vanished. I much prefer to have André Almeida instead of him.
Our young players that can be solution in the immediate future, besides William Carvalho and André Gomes (both have proved that they already belong), are João Mário (Sporting); Bruma (Galatasaray), altought coming from a severe injury and with the instability at the club things aren't looking good for him; and Marcos Lopes (Man City - on loan to Lille), if he chooses to play for Portugal at senior level. Cédric can be a solid player, but nothing more than that IMO,
But in 4 years if the kids have a good development cycle our team will be loaded. Rúben Vezo, Tiago Ilori, Bernardo Silva, Rúben Neves, João Cancelo, Bruno Fernandes and a bit further down the line Gonçalo Guedes (probably the most talent kid to come of Benfica's academy since Rui Costa. A diamond in the rough). All of them have great potential. Kids that may reach a bigger level, but I don't see nothing but solid players in the future: Ivan Cavaleiro, Ricardo Esgaio, Ricardo Pereira and Carlos Mané.
Porto and Benfica just need to start give their kids a change, because they already reached the level of Sporting’s academy. Plus Vitória de Guimarães have been producing some very good players.
The problem is that those kids aren’t ready yet, and we are wasting the last years of Cristiano at the very top with a more or less mediocre team.