The Czech has applauded the 34-year-old after his impressive performance against Stoke City on Saturday
Drogba, who celebrated his 34th birthday on Saturday, signed for the Blues from Marseille for a £24 million fee in 2004.
Cech told the club's official website: “Didier profited from [Juan] Mata's beautiful pass and he finished it expertly. He went around the goalkeeper and scored his 100th goal in the English league.
“He has been here nearly eight years and he has an amazing average of goals scored per game.”
Drogba has made over 220 first team appearances for the London club while also playing 84 times for Ivory Coast, scoring over 50 times in those appearances.
"And he did not even play for some time with injuries," Cech continued. "I congratulate him, he is still an exceptional striker."
The striker has not been in his best form this season, notching only five goals in 18 league appearances, and has admitted that it has been his hardest season since joining the London side.