#1 Bertrand Traore
While many might tend to disagree, selling Bertrand Traore might end up being the worst mistake Chelsea ever made. He has all it takes to become a lethal striker.
Chelsea have a sell-on clause on the 21-year-old, meaning they can get him back for 85% of the fee any other club is ready to pay for him. However, the fee might be 10x of what they sold him for – £10.5 million.
He impressed Antonio Conte during the pre-season and many expected him to be on the bench for the Blues last season. But to everyone's surprise, including the player's, he was loaned out to Ajax.
He played exceptionally well at the Dutch club, guiding them to the Europa League final but could not score against Manchester United and win the European competition for them.
He is now at Lyon and is set to lead their attack in Ligue 1 next season. Should he continue developing the way he has been, watch out for clubs making world record bids for him in the coming years.