well first of all Blackett never showed any potential since the time he was promoted to the U21 and loaned after, so it was a big surprise that he got a shot on tour that year. I think at the tour he was very good and desrved to be praised good on the ball and looked composed, we also played possession football so he didn't need to defend much and 5 men defense suited him as well... People who claim he was bad at tour and didn't show signs of promise should open their eyes because he looked very good but it was a preseason and some of us knew it might be a temporary form showed by him but didn't say anything and watched the masterclass Van Gaal at the time trying to get best out of his players, but who wouldn't believe that a donkey Blackett looked like a decent player in all games of tour, didn't look like a fluke... Where as now when people see Eric Bailly playing 60 minutes against Wigan side in a fairly defensive setup where he really didn't have much to do defensively all of a sudden think he's second coming of Messiah, well maybe no, but people just feel optimistic about him the same way they felt about Blackett, and that's only good but people should be cautious what they say about him that he's different to Blackett, he didn't show anything yet to be proved right there, I bet there is no person here who would watch Villareal week in and week out, not even an half of their games to confirm he's as perfect as he looked in his first game for us..
Pereira on the other hand is a player I've been following for 4 years now and I am of the opinion that he's a great player in making and should be given chance, I don't think he looked far behind Pogba at the same age the time Van Gaal arrived to the club but strangely wasn't given chance, if he was sent out, the chance he would become 100m player would be very small as you don't produce thes palyers once in two/three years.. I also don't think that people are comparing his ability and Pogba's but the situation of the talent not given chance who might flee and become a great player elsewhere, and yes they are playing similar position and yes if Pogba comes, Pereira will not see much of the game time, so there is some connections between the two..
In addition to that you are just overreacting, nobody thinks that he will lead our midfield as title contenders, if so highlight it for me...also I don't know about you but there is people who saw him play more than one preseason game