A deal in the region of £1.7m has been reportedly agreed for Cuevas, and the Union Espanola player has admitted that he is delighted to be moving to England.
The 17-year-old told Radio Cooperativa: "Everything went very quickly and everything was settled this week.
"Chelsea were following me for over a year and we have finally reached an agreement.
"I am already taking English classes so I can integrate quickly. It will be a big change. I could account for all the differences there were when I was there. But I am calm and very happy."
Cuevas has scored three goals in 12 appearances for Chile's Under-20 side.