#2 Josh McEachran
When Carlo Ancelotti handed a 17-year-old Josh McEachran his debut against MŠK Žilina in the Champions League group stage, everyone saw something special in the making. He then replaced Ramies against Manchester City, it was the clear that he was ready for the first team.
However, despite impressing under Ancelotti, the midfielder's dream went away when the manager was sacked after the end of the 2010/11 season. What followed was a series of loans where he hardly made any starts.
His career was not given a chance at Chelsea at all and was sold to Bradford City in the summer of 2015 for a mere £750,000. Someone who could have become one of the best in the world was converted into a mediocre player who can't even flourish in the Championship.