The Italian thinks his assistant will make a fine head coach someday and hopes to work on the French striker's confidence.
The Frenchman has 12 goals in 14 games in 2014 — a stark contrast to his intermittent scoring prowess in past seasons when he had competition from Gonzalo Higuain, who joined Napoli in the summer.
Ancelotti, who left Paris Saint-Germain to replace Jose Mourinho as coach, credits Benzema's compatriot Zidane — who was brought on as part of the Italian's coaching staff — with unlocking the striker's confident frame of mind.
"I think Zidane's done fantastic work, especially with Karim," Ancelotti told RMC Sport. "He's communicated a lot with the players and implemented a specific job with all attackers. His work is very important.
"I am very pleased with Zidane. He has a lot of enthusiasm and a lot of knowledge. He understands what is happening on the pitch during a match. I asked him several times if he wanted to play but he told me no. He can still play without problem. This is important when you get into a club, to be able to rely on someone who knows the club very well, as I had done with Claude Makelele at PSG."
Ancelotti suggested that the former Juventus and Blancos midfielder will make a fine head coach eventually, but thinks Zidane shadowing him at the Santiago Bernabeu is a great way to build up some experience.
"I think Zidane will coach a club without any problem, or even a national team," he continued. "But it is better to start with a club. He has everything to make it happen. He still lacks a bit of experience but this is normal. Otherwise, he has all of the knowledge, personality and charisma needed."
The Madrid boss lauded the attacking trident of Gareth Bale, Benzema and Cristiano Ronaldo that has been affectionately nicknamed "BBC" by some Madrid fans.
"For us, Karim is not important only because he scores goals," he continued, "he is important because he helps the team in possession. I love the positional ability and the characteristics of the player. He is not just a scorer: He is a complete player. He is not very different from Zlatan Ibrahimovic, who loves to help at the back and is also a team player.
"The combination Bale-Ronaldo-Benzema is complementary. The fact that Benzema doesn't have competition from Higuain this year may have helped. I think he can still improve, especially his character, to show more personality. He is a very quiet and shy boy. This is where he can improve."