Under-fire Arsenal defender David Luiz has a vital role to play at the club, according to head coach Mikel Arteta.

The Brazil international has come in for criticism throughout his time with the Gunners and his detractors were given more ammunition following an error-strewn outing against Manchester City last month.

Despite that Etihad Stadium horror show, in which he was at fault for the opener, gave away a penalty and was sent off, David Luiz recently earned a new one-year contract.

Amid the mirth from some quarters, Arteta launched a staunch defence of his man, though he did concede that work needed to be done to "stop his weaknesses".

"His attitude and the way he has behaved with everybody at the club, not just in easy moments but in difficult moments, tells me everything about the person," Arteta told Sky Sports.

"He knows the role he has here. You can ask any player in the team how he is with his team-mates, what he brings to the table, and how willing he is to do well at this football club.

"He made a really difficult decision to leave Chelsea with two years left on his contract.

"It was a complicated decision to change clubs in London like that, but he felt it was the right move and that is the type of character he is.

"I will keep pushing him, keep trying to make him better and stop his weaknesses so that all the positive things he has can flourish."

Arteta's support follows some kind words from Bukayo Saka, who praised team-mate David Luiz's influence in his own development after also penning fresh terms.

That kind of mentorship is one of the reasons Arteta thinks so highly of David Luiz.

"I'm sure about how he [David Luiz] is going to treat him [Saka], how he is going to look after him, how he is going to guide him," said Arteta.

"The young players need stable players around them with experience, who have lots of leadership. The way David supports them is very important to us."