After a year out of the game, it was always going to take some time for Manchester United great David de Gea to rediscover his very best form. At least, that was the expectation. The worst-case scenario, however, would be the modern game had simply moved beyond the former Spain international. Would he ever return to his world-leading best? Or had Fiorentina just taken a punt on a player who, in David de Gea, had spent the last 12 months training on his own for a reason? A couple of oh-so familiar failings last weekend raised plenty of doubts. De Gea struggled as Fiorentina lost 3-2 to Atalanta…