Traditionally, the quarter-finals is the stage of the FA Cup when the Premier League's big boys start to command the tournament. However, this year, something has changed. Arsenal and Liverpool fell in the last round, with the likes of Blackburn, Everton and Aston Villa not making it past the third round. So it has come to pass that the final eight consists of only four Premier League teams. Manchester United, Chelsea, Portsmouth and Middlesbrough are the only top flight sides in action this weekend, and it's the Blues' game against Barnsley and Boro's tie at home to Cardiff that will attract the most attention as fans of the Championship sides and neutrals alike look for shocks.

But is it really possible that the underdog duo will pull through at this late stage of the tournament? Although they will go into the game as massive underdogs, Simon Davey's men do have a number of factors working in their favour. For starters, they have home advantage and that could prove vital, with the possibility of some of Chelsea's stars not being able to adjust to the tight confines and intense atmosphere of a lower league ground handing the Tykes something to work off.

They will also have the confidence they got from their last round shock at Anfield and, of course, anything can happen in the course of a knockout game, particularly at this stage of the season when matches are coming thick and fast for the Premier League's top teams and rotation becomes the order of the day.

However, times have changed at Oakwell since that shock win at Liverpool. First and foremost, it has been revealed that playmaker Anderson De Silva will be out for up to seven months after a scan showed a leg injury to be far worse than expected. His influence will be severely missed and it has already shown in their form, which has suffered considerably since mid-February. Back then, they were threatening to push for a play-off place, having seen off then-leaders West Brom a few weeks earlier. But after three draws and a defeat in their last four games, the Tykes are lacking form and, more importantly, goals, having scored just once in that period.

Chelsea, on the other hand, are riding high after a strong recovery from their Carling Cup defeat to Tottenham two weeks ago. An almost embarrassingly comfortable win against Olympiakos in the Champions League followed a 4-0 drubbing of West Ham in the Premier League, results which have proven that the Blues are still strong contenders on three fronts. The cancellation of Frank Lampard's harsh red card at Upton Park will also be a boost and with both he and Michael Ballack showing that they can play together in the heart of the midfield on Wednesday night it's easy to see Avram Grant's side as the favourites to ease into the semis.

Things are not so clear cut for Middlesbrough though. Put simply, Gareth Southgate's side are lucky to have made it to this stage. Despite having the better of their fifth round replay against Sheffield United last week, they were marginally outplayed in the first game at Bramall Lane and could have been beaten in that tie. The Blades also came close to nicking the replay and, were it not for that freak own goal by Paddy Kenny in the dying minutes of extra time, Boro would have had to face up to the lottery of penalties. The last thing Southgate would have wanted after all that then is another dogged Championship team eager to prove themselves, but that is exactly what he's got in the shape of Cardiff City.

The Bluebirds, like Barnsley, were promotion contenders earlier in the season, but a mid-campaign dip has left them languishing in mid-table, ten points adrift of the top six and without a win since their fifth round victory over Wolves. But Middlesbrough are not as daunting a prospect as Chelsea and Southgate has admitted that the priority for his team this season is Premier League survival and not Cup success. Another factor in Cardiff's favour is that they simply need it more than Boro. Despite some fantastic results on the field this season, City have slipped into severe financial trouble off it, with chairman Peter Ridsdale recently admitting that the £24million loan they need to pay off could lead them into administration.

A continuation of their already impressive and lucrative Cup run certainly wouldn't generate the money to pay off what they owe (although a semi-final berth would be handy, especially as they are both being held at Wembley this season), but it would give them a significant pay-day and a morale-boost that they will need should the worst come to the worst. And with fellow Championship side West Brom and League 1's Bristol Rovers battling it out on Sunday evening in the final game of the weekend, there will definitely be one non-Premier League team in the semis, so if Cardiff were to beat Boro and draw either the Baggies or the Pirates in the semis they could begin dreaming of the final with some justification.

Finally, our last featured match is also the weekend's first as Manchester United host Portsmouth in the Saturday lunchtime game. Having shown their desire to win this tournament with that 4-0 hammering of Arsenal in the last round, United are favourties to claim the tie, but don't discount Pompey. Harry Redknapp may not have a Rooney or Ronaldo at his disposal, but he didn't when he was manager of Bournemouth in 1984. And United fans will need no reminder of what happened one cold January day in the FA Cup in that year...