Graham Potter has kept the summer signing on the bench for his first two games in charge of the club.
But Koulibaly, 31, says he is happy to work hard and win over Potter.
Speaking ahead of Chelsea's huge Champions League clash against, he said: "It is true I haven't played under the new manager. But I'm easy. My time will come.
"When I don't play I put all my energy on the work. I am trying to give my best in training to see how him he can use me on the pitch."