Former Arsenal defender Martin Keown has hailed new signing Pablo Mari after he made his debut for the Gunners against Portsmouth on Monday night.

Mari joined Arsenal on a season-long loan from Brazilian side Flamengo in January, but has had to be patient before making his first appearance for the club.

Manager Mikel Arteta decided the time was right for the 26-year-old to play against Pompey, with the Gunners securing a 2-0 win over the League One side.

Speaking to Goal, Keown said that he believes Mari has the potential to become a key player in the heart of Arsenal's defence.

"He didn't have a lot to do apart from his distribution, but he won everything when necessary," Keown said.

"You could see that he was a little bit short of fitness and that they are building him up. He looks to have the basis of a good player there.

"He wasn't rapid, but he was quick enough to deal with all the situations. We were playing against a League One side who had a lone striker so he and David Luiz were able to boss him between the two of them.

"I think it was important that he had Luiz alongside him to talk him through the game. Now we have to give him time, he has to be given more opportunities."

Mari could make his Premier League debut when the Gunners face West Ham United this weekend.