The Anfield boss takes his unbeaten side to Eastlands on Sunday to confront City - labelled the richest club in the world since their Arab takeover - in the Barclays Premier League.

Benitez had warned City that their wealth could cause them problems - and ruled out any prospect of his captain Steven Gerrard ever being interested in a move there.

However, he knows Liverpool must continue to improve themselves to ward off the threat from City to their top-four status.

He said: "In the future you never know how dangerous City's potential will be.

"The one thing we can do is to think about ourselves and try to improve our squad and players for this season and the future.

"Every year you hear about the possible challenges from Aston Villa, Newcastle, West Ham. Now it is City.

"All that means is that we have to do our job right to keep ahead of them all.

"It depends on your own team and to sign the players you need to maintain your own improvement."

City's new Abu Dhabi owners hinted they wanted Steven Gerrard when they took over the club - but Benitez said: "I do not want to talk about the size of any club in relation to us.

"Gerrard is a local player and this is his club. He is a key player for us and he is happy here.

"We are improving every year and he knows that we can win trophies. That is the most important thing.

"You never know about other players, they are professionals and this is football.

"But Gerrard is playing well and if we are improving he will be very, very happy here.

"The key is that he wants to stay here, that is the most important thing. It is not a question of money.

"He has a commitment with the club and the fans, and as a local lad he would prefer to stay here."

The Spaniard continued: "Everyone is talking about them, but any questions about whether the money makes it more difficult for them is one for Mark Hughes to answer.

"They were a good team beforehand, they are a good team now and they will be better in the future.

"Their situation is a part of the game here now, but we just have to think about beating the side they have at the moment.

"They have a great manager, he did a fine job at Blackburn and I am sure he will do a good job at City too."

He added: "I do not know when they can become genuine contenders. They are a good team with good players and a good manager.

"But why not? They can be serious contenders, but there are other teams have spent big money like Aston Villa.

"Other teams are trying to do the same. But you must realise how hard the Premier League is to win, and I am sure that Manchester City will be patient.

"In January, maybe, they will try to do things in the market. But it is not easy, it depends on a lot of things.

"Clubs will ask for more. It can be difficult, so we will see how they operate in January.

"But players need time. It is not easy to sign top-class players from all around the world and expect them to start playing very well from the first game. It is more difficult than that.

"To get Robinho - ahead of Chelsea - was a good piece of business. He can beat players, he has ability and he is a threat. He is a very good player."

Liverpool will have Javier Mascherano back in the front line after the midfielder was rested from the Champions League win over PSV Eindhoven in midweek.