Looks a fantastic talent and extremely complete. Surprised by how skillful he appears in the clips. Also, is it certain that he would play on the right? Because in clips I've seen, he also seems to play a fair deal on the left.
The only thing I say to you and the other posters here is I see him based on potential with 19 years as the best right fullback we have in Portugal, compared with Cancelo, Semedo, Ricardo Pereira, Cedric, Abel Xavier in the past or others.
Of course that doesn't mean nothing based on the present context. And the present context is Manchester United, a even bigger pressure on him to perform, improve and to show his potential isn't based on the fact he played 7 or 8 games for the first team, but on what he has done mainly at UEFA Youth Tournaments, Under 20 WC and Uefa Youth Leagues.
And I say right because he only played on the left side as a short term fix. If this was 10 years ago with Ferguson and Queiroz guiding him I would be more or less relaxed. Now in 2018 under Mourinho I will reserve my judgement.
The only thing I say is don't compare him with Bebe, this kid won the under 17's with Portugal in 2016, was present on 2 UEFA under 19's in 2016 and 2017, and a Under 20 WC on the same year, and possibly 2 years competing on the Uefa Youth League, only didn't played on the last stages this year vs Chelsea because he already played for Porto first team.
Last but not least I think he also played for the Porto B teams who won the under 23's Premier League International Cup.
He is rated by international scouts for what he has been doing in this type of contexts not what he did for 7 or 8 games in Porto first team.
Possibly United anticipated the fact he had 1 year left on his contract and signed him before he renewed and Porto raised the release clause.
A signing for the future.