Marco Silva insists Everton must sign central defender before deadline

• Everton have shown an interest in Lascelles and Mina
• ‘I know what I have to improve. We have to sign new players’Marco Silva has said new central defenders have been a priority since his first day as Everton manager and it is essential one arrives before Thursday’s transfer deadline.Everton’s defensive limitations were again exposed on Saturday when they were beaten 3-2 by Valencia, their fifth consecutive pre-season defeat. Cenk Tosun and Michael Keane scor