WRESTLEMANIA 31

Wrestlemania 31:
Wrestlemania 31 will be one of the most anticipated wrestlemanias.People are curious about the fact whether the undertaker will be involved in action or not. If not then what will be wwe 's role to fill the seemingly  irreparable gap that will be created from his absence.There are still some questions. If he competes then who will be his opponent. A match between the undertaker and sting is the mostly anticipated and rumored one. The question is if the undertaker would be able to give a performance required for a match of that standard and hype considering his age and current physical condition.
Besides undertaker's match there are still many questions surrounding other matches of the card. What would be daniel bryan's role?What john cena will do? What role brock lesnar would play considering his  historic and yet unexpected win over the undertaker in wrestlemania 30?