FA Cup final CountdownRoy Keane expects Manchester United's FA Cup final showdown with Arsenal to be an explosive affair.

After failing to prevent Chelsea from ending their decade-long duopoly, the Premiership's heavyweight pair put their seasons on the line in Cardiff on Saturday. The losers will walk away from the Millennium Stadium and the season without silverware.

Even without the simmering resentment which exists between the two clubs, such a prospect will undoubtedly raise tensions even further.

All three meetings between the pair this season have witnessed unsavoury incidents.

The infamous "Pizzagate" tunnel fracas at Old Trafford in September was followed by Robin van Persie's wicked lunge on Kieran Richardson during December's League Cup tie at the same venue before Keane squared up to opposing skipper Patrick Vieira prior to United's 4-2 Premiership win at Highbury three months ago.

It was only last season that Vieira was sent off for a foul on Ruud van Nistelrooy which triggered the ugly taunting of the Dutchman following his injury-time penalty miss so there is really little surprise Soho Square officials are looking ahead to the weekend with some sense of trepidation.

And while Keane does not expect a repeat of the most recent Highbury debacle, he accepts the competitive juices on both sides will be flowing pretty freely in Cardiff.

"I know FA Cup finals can sometimes be an anti-climax but I think this one will be pretty explosive," he said.

"Obviously there is that bit of rivalry which has built up over the years because we have been so close to each other.

"It is going to be a hard match physically.

"Hopefully the players will not get carried away and they will stay focused on the game but I am sure the referee will handle anything that might get out of control."

Graham Poll earned universal praise for his handling of the fractious encounter at Highbury earlier this year, particularly for the way he kept his head and nerve when dealing with Wayne Rooney's disgraceful four-letter tirade.

Saturday's man in charge is Rob Styles, one of the more card happy referees who has dismissed seven players in the Premiership this term and handed out six yellow cards in last weekend's clash between Manchester City and Middlesbrough alone.

Ferguson though is unconcerned about Styles's appointment, although he did urge the Hampshire official to take into account any nervousness among the players in the high-octane opening stages.

"The early parts of the game will be feisty, just as they were at Old Trafford and Highbury this season," he said.

"Graham Poll found the early parts of the last match quite difficult to handle but he used his experience to get through it.

"There has been this incredible competition between the two clubs over the last 10 years and I honestly don't believe the games are any different now than they were then.

"No one should get carried away with the idea Arsenal are lily white. They will be competitive, so will we and once everything settles down I am sure it will be fine."

If, as Ferguson claims, defender Gabriel Heinze is ruled out, Ferguson is expected to utilise Mikael Silvestre's extra pace at left back, while Phil Neville is standing by to replace his brother, Gary, should his training ground run-out prove to be a double bluff.

With Wes Brown likely to partner Rio Ferdinand in central defence, the only other major selection poser surrounds Darren Fletcher and who would be squeezed out if Ferguson decides to introduce his fellow countryman as Keane's midfield runner.

The chances are Ryan Giggs would make way if Fletcher gets the nod, with Rooney shuffling onto the left flank to leave van Nistelrooy as a lone striker.

Giggs would almost certainly still be on the substitutes' bench though, offering him the chance, along with Keane, to become only the fourth and fifth players in history, and the first for 114 years, to collect a fifth winners' medal.