Rangers will need James Tavernier to be at his very best against Celtic if Scottish Cup success is to be secured. The Gers skipper lifted one of football’s oldest trophies only a couple of years ago but the circumstances couldn’t be more different. It’s not the first time in his Rangers career that James Tavernier has been under pressure and it is a question that has irked Philippe Clement’s main man. READ MORE: Who is James Tavernier? All you need to know about Rangers captain including incredible stats and famous brotherRangers attitude question put to bed by James TavernierThe mentality of …