The flying winger burst on to the scene last season with 10 league goals and 15 assists as Manchester City strolled to the title.
This campaign the 22-year-old already has six goals and five assists in his 13 Premier League matches, and hasn't failed to score or assist in his eight starts.
Unfortunately for Chelsea it's not only Sane they have to contain, with Raheem Sterling (eight goals), Sergio Aguero (eight), Riyad Mahrez (five) and David Silva (five) all deadly in front of goal.
Portuguese magician Bernardo Silva has also settled in his second year at the club as is fast emerging as the heir to the position of his namesake David.
While you wouldn't say Chelsea are struggling, they are definitely experiencing their first form dip under Maurizio Sarri - having only won two of their last five matches and a last outing loss to Wolves.
The indifferent results have coincided with star player Eden Hazard's goalless run, which stretches six Premier League matches after scoring seven in his first eight.
Sarri seems to be struggling to find a balance in midfield with Jorginho starting to get marked out of games and the inconsistent form of Mateo Kovacic and Ross Barkley.
A bright spark has been the improvement and form of young English talent Ruben Loftus-Cheek, who has scored in his last three Premier League appearances, and also nabbed a hat-trick in the Europa League against BATE Borisov.
Despite being at their Stamford Bridge home, Chelsea will face the ultimate test against a Manchester City team that has only conceded two goals on the road this season.