#2 Aaron Wan-Bissaka

The English defender has been one of the best Premier League rising stars this season. He has been an undisputable choice for Roy Hodgson's Crystal Palace at just 21 years of age due to his brilliant and consistent performance.
An impenetrable wall at Palace's right-hand side, Wan-Bissaka has amassed 4 tackles and 2.2 intercepts on average in the Premier League. He would be an instant upgrade for Azpilicueta in defensive aspects as well as adding more energy to the team.
However, he might need to improve his 72.6 percent on average passing accuracy to suit Sarri's attacking style at Chelsea. His attacking contributions is not that bad for a player with just 70 percent accurate deliveries as he has contributed 2 league assists this season.
His prime years are miles ahead of him and there is still a huge room for improvement for the Englishman. Hence, he would be a good signing for Chelsea.