Former Arsenal and Chelsea star Emmanuel Petit believes "physical power" is what will help the Blues beat the Gunners on Sunday.

He believes that the Blues have a much more balanced squad when it comes to technical ability and power, and insists that it will cause Arsenal problems when they do not have possession of the ball.

"I think they have a great balance to their squad and they have a bigger physical presence. You look in midfield and Chelsea have Cesc Fabregas and Nemanja Matic," Petit said, as quoted by the Mirror.

"You look at the central defence, with John Terry and Gary Cahill. Arsenal are great when they can play their normal game, on the grass, passing along the ground."

"But if they lose the ball, they are not well­ equipped to win it back. I believe that is where Chelsea have an advantage," the French midfielder explained.

The former French international has accused the north London club of a lack of power in their defensive unit and believes unless they can pay their passing game, there is no way that they can beat Chelsea.

"They have players who are great on the ball, don't get me wrong. But when they lose possession, they seem to have a problem. When they can control a game, great," the former Gunners midfielder added.

"But they do not seem to score many from set-pieces while Chelsea are always a threat from that kind of situation. At times, it seems like Arsenal have forgotten how to defend. They are missing some power in their team."

Petit has earmarked Arsenal's club record signing Mesut Ozil as the man, who can help the Gunners grab victory over the league leaders.

He believes that the Emirates Stadium outfit have a chance at victory if they can control the game playing their style of possession football.

"It is a good chance for him to show what he can do. He is a good player – a very good player. He has proved that. But, if Arsenal are to win, their passing game will be the key and Ozil can use this occasion to show just how talented he is," the former Chelsea midfielder explained.

"If Arsenal control the game, playing their way, that will be a chance for them," Petit concluded.