Drogba, who marked his birthday weekend and Chelsea's 107th anniversary with his eighth goal of the season.
"It was the winning goal, so he'll be very pleased for his 100th goal as well," said Di Matteo, who admitted the out-of-contract forward's future was out of his hands.
"That's not for me to discuss. The club will make their decision when it's the time to make it."
He added: "He's been great for this club."