Arsenal boss Mikel Arteta admits there's been little discussion about a new contract for David Luiz.
The 33-year-old defender has started five of the last six games for the Gunners across all competitions, helping Arteta's side keep four clean sheets along the way.
Luiz was named man of the match during the goalless draw at home to Manchester United on Saturday.
"It's credit to him because he trains really hard," Arteta said when asked about Luiz's performances.
"This season has been really tough in the beginning because he's been through some injuries but he's kept at it, he understood his role, he knows his role in the team, he's one of our leaders and he's so willing to keep improving.
"He knows the things that he's really good at and the things where there is still room for improvement. He's a really honest man with himself. He's won everything and it's a joy to work with him.
"He's a great example for them (the youngsters). He's got a good mixture with them between some banter and then some stick.
"They all listen to him because of who he is and what he's done in the game. But also because how he behaves every day, how professional he is and how he goes about the job. He is one of the key role models that we have in our team."
Despite being full of praise for Luiz, Arteta admitted there have been no discussions over a new deal for a man whose current contract expires at the end of the season.
"He showed his character first of all with the decision he made to join the club when he was with a club where he was winning trophies and he was still comfortable and under contract.
"And he wanted a challenge. And at that age it tells your everything because normally at that age the challenge is not sporting but more a financial decision that you take to go to a different country.
"But David loves this game so much and he wants to keep playing at the highest level in a very competitive league. This is the challenge that he's enjoying at the moment."
When pushed to say whether he wants Luiz to stay at the Emirates Stadium, Arteta added: "What I want is for him to keep performing like this to the end of the season."
