Adam Johnson and Pablo Zabaleta sign new deals at Manchester City

Adam Johnson has committed his long term future to the club (GETTY IMAGES)

Manchester City boss Roberto Mancini wants Adam Johnson to concentrate on becoming an even better player after handing the winger a new contract.

City announced this afternoon that England international Johnson has signed a new four-and-a-half year deal at the Etihad Stadium.

Mancini recently admitted he had been harsh in his criticism of some of the 24-year-old's recent performances but only because he believes he has the ability to become a world-class performer.

Now the former Middlesbrough prodigy, signed in a £7million deal almost two years ago, is committed until the summer of 2016, Mancini expects him to fulfil his potential.

The Italian said: "Adam is a good player for me. I think he can improve a lot, though.

"After signing a new contract we have time to talk regarding this.

"I am sure (he is going to get better)."

Johnson, who has started just six games in City's star-studded side this season, agrees there is room for improvement and wants to stay to prove himself.

There had been speculation suggesting his future might lie elsewhere but Johnson is excited by the challenge at City, who currently top the Barclays Premier League and are competing in the Champions League.

Johnson told the club's website, www.mcfc.co.uk: "I wouldn't have signed if I didn't see a big future here.

"This club's going places and I want to be up there with them at one of the top clubs in Europe.

"I want to become a top player, I want to keep winning things and picking up medals.

"This is such an exciting time to be at the club, things are moving so fast and there's been something new every day in the two years that I've been here.

"It's great being part of it - my game's improved, I'm playing for England and in the Champions League, that probably wouldn't have happened if I hadn't come here."

News of Johnson's contract came at the same time it was confirmed that Argentina defender Pablo Zabaleta had also signed a new deal.

The 26-year-old has not been a regular starter as Mancini has rotated his full-backs but his versatility has made him an important member of the squad.

Zabaleta, who would have been out of contract next year, said: "I didn't think twice, I gave a quick answer because I was so happy to sign."

Mancini today underlined his faith in midfielder Nigel de Jong, insisting his contract situation has not affected his form.

The Dutchman has not featured in the last two Premier League games against Wolves and QPR but Mancini says there is nothing untoward, especially given the player had a spell out injured earlier this season.

Mancini said: "Nigel is an important player for me and the squad but he had an injury and he was out for two months.

"After that he came back and the squad played very well. I can't change the squad in this moment but he has played three or four games in the last month.

"I don't think we have a problem for the contract. He has this year plus another year. We have time to talk regarding the contract."

De Jong could come up against Newcastle's Hatem Ben Arfa as City return to Premier League action after the international break tomorrow.

Ben Arfa broke his leg in two places in a tackle from De Jong when the sides met in October last year.

It has emerged this week that Frenchman Ben Arfa, who was sidelined for 11 months, is to accept an apology from De Jong and Mancini is pleased the players can bring the matter to rest.

Mancini said: "This situation can happen in a game.

"It is important that Ben Arfa has come back without problem and can play, for me he is a good player. This is important."

Tomorrow's match at the Etihad Stadium brings together the last two unbeaten teams in the competition and the most prolific attack against the meanest defence.

City have scored a remarkable 39 goals in 11 games in the process of opening up a five-point lead at the top while third-placed Newcastle have conceded just eight times.

Mancini said: "I think their confidence is 100%, they play very well.

"In this moment they are a strong team and they have conceded few goals.

"My memory of last year at home against Newcastle - we had a big problem.

"From last year, they have improved a lot. I think tomorrow will be a tough game for us."

PA