Mikel Arteta wants David Luiz to act as a leader to his Arsenal squad after being impressed by the defender's attitude.
Luiz moved across London as he joined the Gunners from Chelsea in the summer but had struggled to improve a porous backline in the opening months of the campaign.
The Brazil international has impressed since Arteta's appointment last month and put in a man of the match display in the 2-0 victory over Manchester United on New Year's Day.
Luiz, 32, won six major honours during two spells at Stamford Bridge and is the only member of the squad Arteta inherited from Unai Emery who has lifted the Premier League trophy.
Emery had previously held a blind vote among his players to nominate a captain and leadership group but – given he had only just crossed the capital divide – Luiz did not make the cut.
Arteta, however, was unequivocal when asked if he wanted Luiz to be a leader in the Arsenal dressing room: "Yes, that's what I wanted to demand of him.
"He is a player that has won more trophies than anybody else in that dressing room. We have to use that in a very powerful way.
"I wanted him to step up, I wanted him to put all his qualities – his personality and his experience – towards the team and he made a big step forward. I am very very pleased with him.
"In the games he has played under me so far he has been terrific. His attitude in training, the way he communicates with his team-mates, his desire to still learn, it's superb. I am delighted with him."
Arsenal have kept only four clean sheets from 21 Premier League games so far this season as their defence continues to prove an ongoing issue in the fight for a top-four finish.
The Gunners sit 10th in the table ahead of Saturday's trip to Crystal Palace with Arteta revealing he has been working closely with the defenders at his disposal.
"I have to share my principals and what I expect from them in every situation on the pitch," he said.
"It might be a little bit different from what they do with other managers, but positionally they have to understand what I expect from them."
Pushed on what sort of things he has been working on, the former Manchester City assistant added: "Different types of drills.
"Drills where they are facing the ball when the ball is far from them, situation where they have to defend transitions when they are overloaded, when they are in equal numbers.
"When the ball is with the full-backs, what I expect from them. Where I want the line in relation to the ball, not just the opponent, a few things that for us are important."
