Keown, who won three Premier League titles at Arsenal, spoke against the signing of Luiz from Chelsea in 2019 and – despite being won over to some extent – believes the club should return to the transfer market in the summer to land another defender.

"When he came I said it was the wrong signing," he said.

"I didn't wait for six months or a year, I just felt it wasn't the direction I would have gone in.

"I was looking at it from a defensive point of view, as what I'm looking for as a priority for a top defender in a one-v-one situation.

"David Luiz has surprised me with how well he has done but he needs to be in a back-five. He plays his best football in a five and at the moment we are playing in a four so there is always that vulnerability.

"For that reason I would like to go in a different direction – we will see what happens in the summer, they should be looking at strengthening, they have got to be."

Luiz is out of contract in the summer having signed a one-year extension in 2020.

It has been rumoured talks will soon begin on another 12-month deal but Keown believes it may not be a good idea for club or player to do so.

Speaking as an ambassador for the FA and McDonald's Grassroots Football Awards, Keown added: "Having not worked with him I don't know what type of personality he is, only the manager will know that.

"If he feels he is a good influence and he can help the youngsters, because there are a lot of young players that we need to look after and give them the right set of ideals moving forward.

"We are talking about someone who would think of the team before themselves if they weren't playing. I think David Luiz would want to play and I'm sure he still has something to offer the game.

"We all have opinions on defending and his style is not something I am a massive fan of but he has surprised me with how well he has done.

"He has done well in a physical sense in terms of heading and those types of things but I do feel he is vulnerable in one-v-one situations and we have seen that – so I would be surprised if he is kept on for another year."

:: Arsenal legend Martin Keown is launching nominations for the 2021 FA & McDonald's Grassroots Football Awards. To nominate your grassroots hero, go to www.mcdonalds.co.uk/awards