LONDON (AP):

Although Arsenal and Chelsea have been his team's biggest rivals for silverware over the past decade, manager Alex Ferguson believes a club much closer to home will be Manchester United's chief adversary for years to come.

Propelled by the cash of its billionaire owners, Manchester City has become a regular contender for trophies for the first time in a generation.

The two Manchester clubs meet for the third time this season tomorrow in the third round of the FA Cup in what is rapidly emerging as England's most high-profile match-up.

With another Premier League game scheduled for April 28 and the potential for an FA Cup replay as well as a meeting in the knockout stage of this season's Europa League, the neighbours could be seeing a lot more of each other in the near future.

"The way we and our supporters should look at it is that we may as well get used to it because they are not going to go away," Ferguson said.

"We have to get used to the fact that City are going to be challenging for competitions along with us. There's every chance we're going to meet at some point ... on average it's going to be pretty regular."

While City head into the match at Etihad Stadium as favourite with British bookmakers by virtue of an unbeaten home record in all competitions this season, this may well be a good time for United to take on Roberto Mancini's team.

City, the FA Cup holders, will be without two main holding midfielders, with Gareth Barry suspended and Yaya Toure joining his brother and teammate Kolo in linking up with the Ivory Coast squad in Paris today ahead of the African Cup of Nations.

Yaya Toure, who scored the winning goal in City's 1-0 victory over United in last season's FA Cup semi-final, has arguably been the team's most consistent player this season.

Mancini is also without Mario Balotelli (ankle) while fellow striker Edin Dzeko is nursing a knee problem.

"I have one striker and two midfielders," claimed Mancini, whose team plays Liverpool on Wednesday in the first leg of their League Cup semi-final.

United will also be desperate to make up for back-to-back defeats in the Premier League which have left the team three points behind City at the top of the standings.

Ferguson said on Friday that he has no fresh injury worries after the 3-0 loss at Newcastle on Wednesday, with defender Chris Smalling not yet recovered from a bout of tonsillitis.

There is plenty of opportunity for major upsets in the competition this weekend, with many of the Premier League teams entering the draw at the third-round stage facing teams low down in English football's league pyramid.