I think that with the case of Pereyra, is that a lot of us are comparing him to other depth signings that have taken place in the last few seasons.
In my opinion, the depth signings of the past were merely to be, shall we say, placeholders. Very safe types of players, where you can play them a few matches here and there against the smaller clubs, maybe a Coppa Match or two. Matches or situations where there can not be any harm done.
The situation with Roberto is vastly different though. Depth players of the past would certainly have not gotten the amount of run that he has in the past few months. Some may say that it is because of injuries or poor form from other players or what not, but the fact remains that depth players of the past would not have played the amount of minutes that he has in important matches. He brings something different. He doesn't merely just hold down a spot, he can allow the coach to have more options, not just throwing him out there and hoping he doesn't screw up, which I know, from being on this forum for at least a decade, that it was always the best that we could hope for when a depth player was inserted into the starting XI.
They certainly would not have played in without a shadow of a doubt the most important match of the year so far, in arguably the most hostile environment this club has played in, and not only played the full match, but was a protagonist. Regardless of the form that was being displayed by Borussia Dortmund, the fact that he played, and played very well in a match that had credibility and financial implications for Juve, says something about him, and it speaks volumes as to how the coach and management view him.
Giaccherini, as adorable and hard working as he was, would have never ever seen the pitch for either one of those round of 16 matches, and wouldn't even be on the bench for the Monaco ties.
Do I think he's world class? No.
Will he ever be? Doubt it
Is he a good player that is getting better? Certainly.
And you can't understate what it means to have him selected to the National Team. This isn't like being selected for Italy, where the well is pretty dry. Argentina is one of the top teams in the world, so it has to say something when he gets selected.