LET'S not exaggerate, what happens in derbies, decisive matches against competent opposition should matter note that what happens vs the mediocre serie A teams.
But of course we cannot overlook ones career.
Pereyra was never established in a big team and signed vs good opposition, that we failed to dominate and make it easy for him. He is not huge starter material and will never will be, but even such players could become starters under certain circumstances, take bonucci for example, he never was huge material, never will be, but he never had competition for his spot, the team suffers, loses points, games titles because of him and yet here he is, he even have some gay fans!
If bonucci can be a starter, so can pereyra, it's not like we are competing for anything serious anyway...