Manchester United supporters have been enjoying the performances of youngster Alejandro Garnacho over the past few weeks. At the weekend, Alejandro Garnacho took his talents to the other side of the world, when he featured for Argentina. Garnacho, 19, was a half-time substitute as Argentina beat El Salvador 3-0. It was his best performance yet for his country, after a direct, yet unselfish display in which he was unlucky not to end up with at least one assist. This was his fourth international appearance and the young forward could potentially be in line for a first start when Argentina face C…