#1 Aaron Ramsey
Aaron Ramsey's current contract with Arsenal ends in 2018 and Arsenal could be forced to sell him if they want to avoid another Robin Van Persie or Alexis Sanchez contract situation.
He is just 27 years old and is about to reach the peak of his footballing powers. He has been crafted into a box to box midfielder by Arsene Wenger and he has played plenty of football at the top level.
Unlike the other players, Ramsey has the experience of having played in the PL and it will be of immense value, meaning that he doesn't require time to adapt to the physicality of the League.
He likes to break up the play and start attacks for his team and his fitness is the key to it. He can contribute to the attack of his team as well as he can contribute defensively. He also has a good relationship on the field with Chelsea's winter signing, Oliver Giroud.
Chelsea are considering a move for the Welsh international, as they look to strengthen their midfield. He should definitely be an upgrade on Bakayoko, and a very good one at that.