Drogba never caused me any problems declares Chelsea boss
Ancelotti has never tried to change the player's fiery personality since taking charge of the club.
The Italian said: "With Didier, he has particular skills, physically, and obviously he didn't like to train where he's not the best.
"For example, if he needs to run he doesn't like to run because he's not a resistant player.
"But now, with individual training sessions, we have to improve his strength, skill and speed. He likes to do that.
"I do not know what happened in the past with him but ever since I came here he has been the same player. He hasn't changed in this time.
"He's a player with strong personality. He's efficient - he scored a lot of goals last year - but he's focused and knows very well that he's one of the most important players in this team."
The former AC Milan head coach believes the striker could still be scoring goals for the Blues until 2014.
He added: "Drogba is 33 but Pippo Inzaghi scored two goals in the final of the Champions League for me in 2007, when he was 35 and he is now 37.
"Drogba still has time to score two goals in the Champions League final. After 30, you have to improve and do more preventative work and training on the training ground. That's very important. It's different being 30 to being 20.
"But Didier is focusing on this and wants to maintain his power and physical condition.
"He has not had too many injuries and I think he can stay at the top level for four years."