The 19-year-old centre-back is widely thought of as one European football’s top talents, and has been tipped to become France’s captain in future by Les Bleus’ boss Didier Deschamps.
His performances have alerted a number of the continent’s top clubs, including Inter Milan and Monaco.
The duo are ready to mount £9m moves for the teenage sensation, which has alerted Chelsea.
Jose Mourinho is keen to build for the future at Stamford Bridge, and sees the robust and fiery defender as a wise investment.
Despite his age, Zouma is already one of his club side’s most important players and a first-team regular.
However, Saint Etienne may be forced to sell either this month or at the end of the season for financial reasons – as they did over the summer with Gabon star Pierre-Emerick Aubameyang.
Zouma has already developed a reputation for his combative edge, with the youngster having been hit with a 10-game ban this term for reckless on-field behaviour.