The 23-year-old has struggled for consistency at Atletico this season – he has scored four goals and provided three assists in 14 La Liga appearances.
In 2019 Felix joined Atletico from Benfica for £113million, which remains the fourth-highest transfer fee in football history.
Chelsea have scored just three goals in their last eight games in all competitions
So far in this transfer window Chelsea have already secured the signings of Benoit Badiashile (who cost £58million from Monaco), David Datro Fofana, and Andrey Santos.
