Jack Grealish had made an admission on his personal form that should leave Manchester City’s upcoming opponents quaking in their boots. With Liverpool slipping to a shock defeat at Nottingham Forest, Manchester City are now the only team in the Premier League to have won all their games and are sitting pretty at the top of the table. It was far from easy against Brentford on Saturday, though, with the visiting Bees taking the lead after just 22 seconds when Yoane Wissa nodded home John Stones’ slashed clearance. Brentford were all over City and could have gone 3-0 ahead but the inevitable Erli…