The fortunes of a club can change instantly. This is just how it is in football sometimes. One day you’re the “in-form” team that everyone needs to “watch out for”, the next minute you’re “reeling” and your season is “on the ropes”.

Manchester United has been riding this up and down cycle for the majority of the season to date. It’s not something United fans have been used to dealing with during the club’s recent history. An onslaught of injuries to key personnel, inconsistent player performances and a change of leadership have all combined to hamper Manchester United’s progress.

Just a few weeks ago, United were riding the high of a six game winning streak in all competitions after having struggled through the early part of the season. Everything was beginning to look positive at the club and experts were warning Premier League rivals to “beware” of a vintage Manchester United late season push.

But then Tottenham won at Old Trafford to halt United’s progress. A few days later, Swansea City came into the Theatre of Dreams and knocked the Red Devils out of the FA Cup. Immediately after that result, United were dealt a defeat by Sunderland in the first leg of their semi-final League Cup tie.

As quickly as Manchester United had built up some momentum, it had been abruptly cut short, and now the club was “in crisis”.

United were able to reverse their fortune a few days later by beating Swansea City in the league, but they still are miles away from the title contenders (Arsenal, Manchester City and Chelsea) and are five points behind fourth place Liverpool for the final Champions League spot.

With seventeen games left in the Premier League season, the battle for fourth place appears to be coming down to four teams: Liverpool, Everton, Tottenham and Manchester United. A single league defeat, suffered while the other combatants take maximum points, could be devastating at this time of year. If the race for fourth place were between two teams, the chasing team would gain confidence seeing the team above them drop points. But with so many teams battling it out for one spot, the possibility of each team above you losing or dropping points is slim.

None of these clubs will want to lose any more ground on a Champions League spot with so many teams gunning for the financial windfall of European football next season.

That is why four days are vital to Manchester United’s season.

Should all the clubs involved in the chase for the Premier League’s final Champions League position win this weekend, Manchester United would need a result against Chelsea on Sunday or risk falling a maximum of eight points behind Liverpool; in addition to being seven points behind Everton and six behind Tottenham Hotspur.

If that weren’t enough, United face a “win or go home” match against Sunderland on Wednesday in the return leg of their League Cup semi-final. Sunderland’s 2-1 victory at the Stadium of Light has put the Red Devils in this “must win” situation.

United do enter the contest with an away goal to their advantage. But they have not been strong at home this season, while Gus Puyet’s side have been brimming with confidence recently; both in the league and the Capital One Cup. Should Sunderland score against United, the Red Devils would need to find the back of the net three times in order to win the cup tie (two goals would only push the match into extra time and/or eventually penalty kicks).

Over the span of four days, Manchester United could be out of all of their domestic cup competitions and be staring at a monumental task of catching three teams in the race for fourth place in the Premier League.

In October, Sir Alex Ferguson had this to say regarding United’s current season: “For David [Moyes], winning a trophy would be a fantastic achievement no matter what it is – the League Cup, FA Cup, European Cup or Premier League. We’ve always had priorities obviously and David is aware of that but I hope he achieves it. The key for David is to maintain – not do anything better or less – just maintain what the club has done for the last 20-odd years.”

Should United fall further behind their league competitors and be knocked out of all domestic cups, they would still have their Champions League tie against Olympiacos to point towards. The Greek club are a good, but even a weaken Manchester United should be able to navigate its way into the quarter-final of the European event. However, for United to get past the remaining members of the Champions League field would be a difficult proposition.

A trophyless season combined with missing out on Europe would be a result few could have imagined at the start of this year’s title defense. That’s why, more than ever, Manchester United need to rally the troops (the ones who are healthy) and focus on winning the rest of their matches; vital importance being placed on the next two contests.

The negative press which has followed manager David Moyes and the club this season has lit a fire under some of United’s senior players. Darren Fletcher made it known this week that there is a growing anger inside the Manchester United dressing room. The midfielder said: “It is as if some people have been waiting for it to happen and are really relishing it. We’ve got to use that as fuel to prove them wrong. We have got some great, talented young players in this squad. We have to keep reiterating to them that they believe in themselves. They will come through it without a shadow of a doubt and will be better and stronger for it.”

Nemanja Vidic has stated that the team are well aware of the challenges they face in the coming days. In an interview with ‘Inside United’, Vidic said: “We have to win regularly and in the next month we will know exactly where we are. By the end of January and start of February we will show what our position is and what our capability is in the Premier League. Then, of course, the Champions League starts up again. This is an important time for us and we all want to do well.”

The critical four day stretch kicks off on Sunday at Stamford Bridge.