The streak is over. Manchester United surrendered their 10–match unbeaten run against a solid Southampton side, who produced a brilliant away performance to show why they are a genuine top four contender. It is the first time since 1988 that the Saints have won at Old Trafford and the first time since United failed to have a shot on target at home since 2009.

All-in-all, it was a very disappointing day for the Red Devils as they dropped down to fourth place in the table with Arsenal, Tottenham and even Liverpool breathing down their necks in the race for the Champions League. United have to make the most of a good-looking run of fixtures over the next few weeks and re-stabilise themselves comfortably inside the top four.

Here are five key thoughts following the drab performance at home to Southampton.

With players returning, three at the back should have been scrapped

United’s formation has been a hotly debated topic this season but the arguments appear to have been finally ended by another hugely lacklustre performance on Sunday. There are few United fans who still believe that the 3-5-2 formation is the way forward. The system which Louis Van Gaal has been determined to make work since he took over at the club should have been scrapped for this crucial match against a top four rival, especially with injured players returning.

If you look at the strengths of the current squad and the individual qualities that each player possesses, the lack of a top class winger to play on the opposite side to Angel Di Maria would make a 4-3-3 system difficult to implement currently. However, a 4-4-2 diamond which worked quite well for a few games earlier in the season could easily be used to fit in the plethora of attacking talent at the manager’s disposal. Either way, it is surely time to move on from the 3-5-2 which clearly isn’t working.

Three centre backs on the bench? Why restrict yourself?

Jonny Evans, Paddy McNair and Tyler Blackett were all named on the bench for this game, a decision which immediately restricted Van Gaal’s ability to change the game in the second half. The substitutions have been criticised but it was a sheer lack of alternatives that meant the Dutchman was almost forced to throw on Marouane Fellaini in the final stages of the game to try and nick an equaliser. But when Luke Shaw was brought off due to fatigue, a more positive switch than to bring on Blackett was surely the better option.

It is all very confusing when you consider the fact that James Wilson, a raw, hungry and pacey striker was left sitting on the bench at the final whistle when United needed someone to make runs to drag defenders out of position to create space for the midfielders. To confound the misery, Radamel Falcao and Adnan Januzaj, both game-changers when on form were both dropped from the squad altogether. Both would have been good options to have when United needed some inspiration in that second half.

Any Falcao permanent deal appears unlikely after Van Gaal’s decision to drop him

Many eyebrows were raised when Falcao was substituted in the recent draw against Stoke City despite being United’s best player but the decision to leave him out of the squad at the weekend was even more baffling. Despite a poor performance at Yeovil last week, the Colombian was just beginning to show signs of a return to form but Van Gaal decided he was not needed at the weekend despite United lacking attacking options on the bench.

This episode clearly shows that the Dutchman just may not fancy Falcao and lacks confidence that he will ever return to his unstoppable best. Although this may be the case and United may be wiser to not splash out £40million+ to acquire his services permanently, the loan deal was definitely worth the risk when you consider what level Falcao has the potential to play at. But even if Falcao may not be here to stay, the decision to drop him completely for the Southampton game was absolutely ludicrous, especially when you consider the fact that three central defenders were on the bench instead.

Di Maria is wasted up front

The stalemate which was being played out in midfield before the Southampton goal saw Angel Di Maria chasing the ball around like a headless chicken at times. The Argentine was deployed as an orthodox striker, before being substituted after 72 minutes, which in my opinion is a waste of his supreme creative talents. Di Maria hardly had a touch of the ball and looked out of place in a striking role when United were not using counter attacks effectively.

United needed Di Maria’s dynamism and energy in midfield on Sunday. His ability to drive with the ball from a deep area is unique in this current squad and with Southampton choosing to set up with three defensive midfielders; United needed a midfielder who was not afraid to take a risk. Di Maria can produce moments of magic out of nowhere and was wasted up front alongside Robin Van Persie.

It is January and we still don’t know the best team or formation. A worrying thought.

With over half the Premier League season gone, we are still not sure just what United’s best eleven is and in which system they would be utilised in. It is a worrying time at Old Trafford as the Red Devils cannot afford to miss out on Champions League football for a second season running. That would be a disaster. With other clubs having to focus on more competitions, United should comfortably achieve that goal.

I think United will break back into the top four as there is a great deal of quality at the club but Van Gaal must decide on his best team and use a system which gets the best out of each player at his disposal. The Dutchman has got the pedigree and a proven track record so I have no doubts that performances will improve eventually, unlike last season. He has got many things right during his first half season in charge but on Sunday; he got it horribly wrong against an impressive Southampton side.

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