Roberto Mancini challenges Micah Richards to prove ability

Manchester City manager Roberto Mancini has again challenged Micah Richards to prove he is the best right-back in England.

The 23-year-old now has the opportunity to impress another national team boss following this week's departure of Fabio Capello, who had been overlooking him.

Richards has been behind Liverpool's Glen Johnson and Kyle Walker of Tottenham in the England pecking order despite his fine form for the Barclays Premier League leaders.

Mancini has long trumpeted Richards' potential but has warned the defender not to expect an immediate international recall - his last cap came in November 2010 - because he still has much to prove.

Mancini said: "Micah has everything to become a top full-back.

"I think he has improved a lot in the last year but he can still improve, he can do better.

"At this moment for the national team, probably Johnson or Walker are better.

"But I don't want to say Micah can't play for the national team - if he wants, Micah can play always.

"If one England manager has a choice of three - Johnson, Walker, Micah - one of these players stays out.

"Micah played for England with Capello but there are a lot of players in England and one manager can call only 20-22 for a European Championship.

"I think Micah can really be a top full-back but he needs to improve."

City travel to Aston Villa on Sunday having got their title challenge back on track with victory over Fulham last weekend.

Mancini's men endured a difficult January in which they lost to Sunderland and Everton and went out of both domestic cup competitions.

City have also encountered difficulties away from home, having won just one of their last six on the road in the league, but Mancini has played down any concerns.

"It is impossible to win away always, like we did at the start of the season," said the Italian whose team, by contrast, have a 100% home league record.

"You can win away but sometimes you can lose these games. Away games are difficult, not only for us, for all the teams.

"But until now we are top - we have done better than the other teams, away and at home.

"There are some games you lose away that you deserve to lose, but I don't think we deserved to lose any game away.

"Sunderland - we had 70% of possession, 29 shots on goal against two and we lost because we conceded an offside goal in injury time.

"Everton the same - 65% of ball possession with 15 shots for us against five or six for them.

"Chelsea was the same and we lost these three games.

"If you go away and deserve to lose 3-0 it is different but never did any team deserve to beat us away."

City could come up against three of their former players at Villa Park in Richard Dunne, Stephen Ireland and Shay Given, the last two of whom Mancini sold.

Mancini, however, does not believe the trio's past will be a big factor in the game.

He said: "We are not playing Manchester City against Ireland, Given and Dunne - it is Aston Villa against Manchester City.

"Aston Villa are a good team, they have good players and if we want to win in Birmingham we must play a very good game.

"The other things are not important. Shay and Ireland are playing in a good team."

City have been without their midfield inspiration Yaya Toure and the defender Kolo Toure since the January 3 defeat of Liverpool due to their involvement in the African Nations Cup with Ivory Coast.

That tournament ends as the brothers face Zambia in the final this weekend and Mancini is keen to get them back into his side.

With no game next weekend due to City's elimination from the FA Cup, the pair are likely to travel to Portugal for Thursday's Europa League game against Porto.

Mancini said: "We are lucky because after Sunday we have only one game in Porto, the first leg of the Europa League, and after we do not play in the Premier League.

"We have time to recover for Yaya and Kolo."

Striker Mario Balotelli also misses the trip to Villa as he serves the last game a four-match ban.

PA