The initial outbreak forced the postponement of Tuesday’s trip to Brentford, when it is understood United had nine players available, and now the Old Trafford fixture with Brighton has also been called off with the outbreak in the squad worsening.
Even if the next scheduled game away at Newcastle goes ahead, it will have been 16 days between matches since they won 1-0 away at Norwich.
It means Ralf Rangnick will be given plenty of time to mull over his squad in the weeks coming, and he has five selection issues that need to be solved before United next take to the pitch.
MEN Sport run through them here:
Not always right
Diogo Dalot has been one of the success stories of the Rangnick reign so far, but he will soon face fierce competition from Aaron Wan-Bissaka as the former Crystal Palace man looks to regain his spot in the starting line-up.
Based on recent performances, most United fans would pick Dalot to start the next time United take to the pitch, but over the festive period, Wan-Bissaka could influence the thinking with his approach on the training ground.
The Englishman has failed to develop as quickly as required to rival other right-backs in the Premier League, and if he doesn’t kick on now, he could become a peripheral figure at Old Trafford.
On the left
On the opposite side of the defence, Alex Telles is enjoying his best form at United but is another player facing stiff competition from Luke Shaw, a year after his arrival sparked a resurgence from the England international.
Rangnick has made clear his desire for attack-minded full-backs and it is something that has worked wonders in favour of Telles, despite his obvious defensive limitations.
It is safe to say Shaw is still the more well-rounded option of the two. Now he needs to find a way to get back into the starting line-up, though it doesn’t look like he’ll ever be able to monopolise the position so strongly again.
The return of Varane
One quirk of the fixture cancellation is that United should be boosted by a fully fit Rapahel Varane by the time they next play in the Premier League, a huge benefit to Rangnick and his defensive overhaul.
The German coach has identified a need for more clean sheets if United are to stabilise their season, and they certainly have a better chance of doing so with the Frenchmen at the heart of their defence.
United have recorded successive clean sheets in the league under Rangnick so far.
The conundrum is who he actually comes in for, though, with Harry Maguire yet to hit his stride this season while Victor Lindelof has arguably been the more reliable alternative. It seems highly unlikely that the club captain will be dropped, but it is certainly food for thought.
Van de Beek or Fernandes?
Rangnick appears to have settled upon Fred and Scott McTominay as his central midfield partnership, but there is still work to do in regards to his attacking quartet of players as he looks to fine-tune the team.
Bruno Fernandes’s form, in particular. This season, the Portuguese has led the way in chance creation for United, but in recent weeks, he has struggled to adapt and is attempting too many impossible balls in the final third.
For the new formation to work, United need to have better control of matches, and there is an argument to suggest that Donny van de Beek would provide that in a playmking role. The Dutchman seems the ideal fit for the tactic, but it likely means playing him instead of fan favourite Fernandes.
The final big call comes in attack, where United are still experimenting with their forwards and who makes the best partner for Cristiano Ronaldo.
Marcus Rashford has been favoured in recent weeks but appears to be keeping his place based on work rate rather than his current form, with Mason Greenwood surely deserving of an opportunity given his regular level of performance.
Edinson Cavani should also be close to a comeback by the time United play again, and he has already proven to be a good strike partner for Ronaldo this season. His ability to press with ferocity may also impress Rangnick.
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