Aston Villa winger Moussa Diaby must now show his worth to Unai Emery, starting in today’s fixture against Everton. Unai Emery has built up a solid reputation for significantly improving his players prospects. When he arrived at the club, Ollie Watkins was far from a clinical striker but now only Erling Haaland and Mohamed Salah have produced more goal contributions than him in this season’s Premier League. Similar can be said for Douglas Luiz, who has been transformed into a serious attacking weapon, matching some of the league’s best-attacking midfielders since Emery took to the helm. He’s a…