Arsenal title winner Martin Keown admits he has doubts about manager Mikel Arteta.

Keown says he is concerned over Arteta's persistent backing of defender David Luiz.

"I would never have signed the player in the first place," Keown told talkSPORT. "But he's there and he [Arteta]'s got to make the most of it.

"I don't think he's blessed with too many options.

"But it is worrying that Arteta is backing a player who probably isn't quite good enough, I think there's no doubt about that. I don't want to humiliate the player further, we all have bad performances, but it's one after another."