adidas Chelsea Youth Mystery Jersey 16/17. What is it? The fan jersey mystery box contains one Manchester United youth jersey (could be home; away; or third) with one of you r favorite Manchester United players including Pogba; Ibrahimovic; Rooney; etc.You just tell us what size you\'d like and w e send you one jersey from the 16/17 season.The jerseys you receive could be any player. All jerseys are official merchand ise and include the authentic customization. Products might show signs of wear or have cosmetic imperfections. Mystery kits are; o f course; nonrefundable/nonnegotiable.