#1 Nemanja Matic
Matic was sold to direct rivals Manchester United for the same amount that the Blues spent on Danny Drinkwater, making it the stupidest sale Chelsea have made this season.
In front of the Chelsea defence, Matic was a wall and helped the Blues secure 2 Premier League titles in 3 years.
He may not have the stats to prove his abilities, but those who have seen him play know what he bought to the team.
With the ability to hold the ball and protect those behind him, Matic helped others play better football and will continue to do so in the coming years at Old Trafford.
Also read: Five attributes of Nemanja Matic Chelsea will miss
His replacement - Tiemoue Bakayoko will face a tough task filling in the void created by the departure of the Serbian midfielder.
Chelsea will hope that Matic brings only his skills to Manchester United and not the title.