Carlo Ancelotti admits David Luiz must learn to calm down after narrowly escaping being sent off in Chelsea's win against Manchester United.
The new Â£25million signing was lucky to avoid a second yellow card for a cynical foul on Wayne Rooney during Tuesday night's controversial game at Stamford Bridge. The 23-year-old's aggressive approach marred what was otherwise another virtuoso display from the Brazil defender, who had scored a stunning equaliser minutes earlier.
"He has to know English football," Ancelotti said. "He has to be more calm on the pitch."
He added: "Obviously, he's showed fantastic ability and quality.
"He has to improve, but he will because he'll have more experience and knowledge about English football. He can change his behaviour on the pitch."
Luiz's all-action performances have made him an instant hit with the Chelsea fans and Ancelotti believes there is even more to come from the gifted centre-back.
"He's showing fantastic ability offensively, obviously," said the Italian, who has worked with some of the great defenders of the modern age, including the legendary Paolo Maldini.
"He's able to pass the ball and move in front without problems. He's able to shoot at goal.
"Defensively, he can improve."