Wenger says Chelsea to do not have the heritage of some of the other bigger teams in the world

The Frenchman insists it will take more than success on the pitch to make the Blues the top outfit on the planet.

According to Wenger, Chelsea do not yet possess the rich history, pedigree and fan base of clubs like Real Madrid.

"At the moment they are a bit premature to say what they will do," said Wenger, whose Gunners side face Chelsea at Stamford Bridge on Sunday.

"Playing the best football is one of the things that makes a club bigger. You also have the natural size of the club built through history.

"It will always be that Real Madrid are bigger than Alaves, even if Alaves has a better team for a few seasons.

Whether Chelsea can become the biggest club in the world is also down to the size of the fan base Arsene Wenger

"Also you have the accumulation of history with players who are faithful to the club. A lot of things come into making a club big.

"Arsenal is a club that you could easily underestimate in terms of size because when we built the stadium we had the question, do we make 50,000, 55,000 or 60,000 seats?

"With a good team today maybe even 60,000 is too small.

"Whether Chelsea can become the biggest club in the world is also down to the size of the fan base. That takes a very long time to build up."

Chelsea chief executive Peter Kenyon made the claim that the Blues have the potential to be the world's most powerful club by 2014 when he recently laid out his vision for the future of the club.

Of more importance to Wenger as the two London rivals prepare to meet is the state of his own team.

After a recent rocky spell when they suffered successive defeats to Bolton and Fulham, the Gunners bounced back by beating Tottenham and then qualifying for the knockout stages of the Champions League.

Now Wenger is full of optimism and upbeat about Arsenal's prospects on Sunday - even if he has yet to taste victory over Blues boss Jose Mourinho.

Since the beginning of the season the team has shown character in the big games, and that's why I'm confident Arsene Wenger

"It does not bother me that I haven't beaten Mourinho. I am confident that we can make something special happen," said Wenger.

"We had a cloud over us for a while because we had not qualified for the Champions League until Wednesday and there were one or two disappointing results in the league.

"But since the beginning of the season the team has shown character in the big games - and that's why I'm confident."

Wenger has also made light of the loss of Ashley Cole following the left-back's high-profile defection across the capital.

Cole is preparing to face his former club for the first time since his acrimonious transfer to Stamford Bridge on transfer deadline day.

But Wenger insists Arsenal have the perfect replacement in Gael Clichy and is backing the 21-year-old French defender to match the achievements of his predecessor.

Gael Clichy is being tipped for a big future by Arsene Wenger

"Clichy is the answer to losing Cole - 100% the answer," said the Gunners boss, who was without the services of Clichy for the first part of the season because of a foot injury.

"When we lost Ashley Cole we knew we had Clichy but he was injured. And what he is doing now after being out for so long is quite amazing.

"It's a good challenge for him because he will be compared to his model. He always said Ashley Cole was his model and tomorrow he will be compared to him.

"Clichy has the potential to be as good as Cole. Ashley is playing well at the moment and I am not surprised by that.

"When we lost Ashley Cole we lost a player who was 25 years old and that's the best age for a football player. We lost a big player."

One interested observer on Sunday will be Manchester United boss Sir Alex Ferguson.

After his side extended their lead at the top of Premiership table to nine points, with Saturday's 3-1 victory over Manchester City, he is hoping Arsenal can do him a favour by beating second-placed Chelsea.

"I will be supporting the Gunners for a change," said the Scot.