It's a difficult one isn't it? He is our most valuable, most important player and he does sacrifice himself for the team in lots of important ways. He works very hard, and has a very unusual skillset for a forward.
At the same time, he's sometimes lets his desire for goals overtake the team's need for goals. This is usually reflected in poor decision making in the final third (ie shooting when there is a tap in for someone else, running offside and staying offside for the entire run), and then grabbing a freekick when you have James, Digne and Gylfi who are clearly the designated takers. I know Ancelotti covered for him by saying he was on the list of takers, but I don't believe that for a moment. That's diplomatic man management.
It's not an easy balance for Ancelotti to strike to give him confidence and to get him to keep putting himself on the line for the team, but also keeping his ego in check to make better decisions and try to think of what the team needs more than what he needs,