Just when we thought Bradford City’s incredible journey to the League Cup final last week was the story of the season, this weekend’s FA Cup carnage had many of us sat gob smacked, staring at our television screens in amazement.

The reigning European Champions were almost toppled by League One’s Brentford - a game which saw the underdog look like the top god for 70 minutes or so – MK Dons destroyed a weakened Queens Park Rangers side, Leeds United toppled a near full strength Tottenham, Norwich City were beaten by non-league Luton, and Liverpool were beaten by a team with just three sides to their ground, Oldham Athletic.

After I’d stopped laughing on Sunday night – more because I didn’t know how else to react to a weekend of pure unpredictability then out of any joy taken in seeing some of England’s elite clubs in such bizarre circumstances – a question dawned on me.   How important is the FA Cup as a trophy at this point?

Sure, we saw some teams play a number of reserve team players and youngsters this weekend but now we’re in the business end of the competition, and four clubs will mean business.

With plenty of the Premier League’s ‘big dogs’ out of the competition, just four real challengers remain in the competition, and those four could easily end up being the Premier League’s final top four come the end of the season.

So who does it mean the most to?

Arsene Wenger’s last piece of silverware was the 2005 FA Cup trophy. Eight years later and Wenger sits atop a very fragile throne at the Emirates.  The fans continue to call for his departure with every loss, while a major share holder in the club, Alisher Usmanov, has accused the French manager of turning the club into a feeder club for it’s rivals. A cup final victory could save his job at Arsenal at the end of the season, or would boost his own stock in the managerial market, should he and the club part ways this summer. Either way, with just three major rivals remaining in the draw, expectation on Wenger to deliver the goods this season will now be as high as ever, especially with a home draw against Blackburn awaiting in the last 16.

Roberto Mancini’s first trophy at Manchester City came two years ago when his side beat Stoke City at Wembley in the FA Cup final.  Last season his club pulled off the most dramatic Premier League win we are ever likely to see, and the weight of expectation for the Italian to bring another trophy to the club this season is huge. It was supposed to be the Champions League – a natural progression of FA Cup, to a league title, and then to European glory – but success in Europe has evaded the former Sampdoria player on his first two attempts as a manager at the Etihad.

With United leading the title race, there is a strong possibility that, unless a long, grueling, Europa League competition is taken seriously this year, the FA Cup could be the only piece of silverware Mancini will have a chance to grab this season. And with Jose Mourinho looking ready and available to take a job in the Premier League in 2013/14, Roberto will need something in his trophy cabinet to persuade the City board to stick with him for another season.

Mourinho’s potential availability this summer will also have been noted by Roman Abramovich and his interim manager at Chelsea, Rafa Benitez. 

While fans in Madrid may like the idea of a Rafa, Jose, swap deal with The Blues, the Spaniard has made it know that he would be keen to carry on at Chelsea and make his position at the club a more permanent one.  But having lost to Southampton, and drawn with QPR, both at home, and having been unable to get past Brentford at the first time of asking in the FA Cup fourth round, Rafa’s position at the club is hanging in the balance.  The fans don’t want him, and Abramovich has been livid with his caretaker manager already this season after poor results. Now, having been knocked out of the League Cup, and being 11 points off the top of the table, Chelsea must rely, like City may have to, on either the Europa League or the FA Cup for silverware. And if Rafa wants the job, he’ll need to bring one of those to trophies home.

All three of these managers are looking at the FA Cup as a way of potentially ending their jobs, but one manager might use it to bring his to an end.

Sir Alex Ferguson is the most decorated manager in Premier League history and has managed United for over 25 year. Many have wondered when Sir Alex will step down from his role as the all powerful leader of the Red Devils, and some thought it would happen two years ago after his side reached the Champions League final at Wembley. But their crushing loss to the always-impressive Barcelona appeared to give the Scotsman renewed vigor as he looked to topple Barcelona off their perch in European football. 

Barca, though, have gone from strength to strength in the last two years, and their crown looks far from slipping off the top of their heads. Ferguson could easily admit defeat and accept his United side to be second to the Catalan giants and no one would hold it against him or his impressive record. So would then, a league and cup double be enough to move the Sir Alex out of the dugout at Old Trafford.  He would leave the club two league titles ahead of Liverpool and at the top of English football with its two most important trophies. 

It would also give him the opportunity to deny three of his clubs biggest rivals, and three of his most disliked managerial rivals, a trophy they all need to win.

All four managers would love to get their hands on a trophy many consider to be far less prestigious or important as it was 30 years ago, and with us entering the business round of the cup – assuming Chelsea will get past Brentford in their fourth round replay at Stamford Bridge – the importance of this years FA Cup just went up a few notches.