The full-time whistle at Old Trafford on Saturday signalled the end of a truly disappointing week for Manchester United.

Although United lost to BSC Young Boys in the Champions League, there were mitigating circumstances for that defeat, and prior to the new week starting, the Reds were unbeaten in the Premier League are level on points with rivals Chelsea and Liverpool.

Seven days after David de Gea's heroic penalty save away at West Ham, though, and United have been knocked out of the Carabao Cup and defeated at home in the Premier League to Aston Villa - an awful pair of results.

Rather worryingly, Aston Villa's 1-0 win at the weekend was well deserved and Dean Smith set up his side to attack with no fear against United, which paid dividends when the visitors had Ole Gunnar Solskjaer's side immediately shaken and uncomfortable, reminiscent of Oleksandr Usyk's win over Anthony Joshua later that day.

There was a cohesion and fluidity about Aston Villa's attacking play that has lacked from United's transitions this season and they asked questions of Aaron Wan-Bissaka, Raphael Varane, Harry Maguire and Luke Shaw, seriously testing their credentials.

While Shaw and Maguire would eventually be forced to leave the field through injury, it's worth noting that the back four that Solskjaer trusted to start the game were signed for a total of £200m and the signing of Varane was supposed to be the last piece of the defensive jigsaw at the club - United appeared to finally have a worthy title-challenging defence.

Cristiano Ronaldo has completed his return to Manchester United.

Manchester United enjoyed a sensational transfer window, securing the signings of Jadon Sancho, Raphael Varane and... oh, yes, Cristiano Ronaldo.

Now, Ole Gunnar Solskjaer will be under pressure to deliver silverware with his star-studded front line. We cover every angle of the club at the MEN and with our dedicated United newsletter, you'll never miss a headline. It's free and there's no spam.

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The need to find Maguire an elite centre-back partner was fulfilled with Varane. But while the English centre-back enjoyed an impressive comeback from injury with England at the European Championship - leaving United fans dreaming of what a potential Maguire and Varane partnership could bring - he's delivered multiple below-par performances since his return to United.

Maguire is yet to be individually punished by the opposition, but there have been uncharacteristic glimpses of clumsiness and fragility from the United skipper at the back, just like when he asked too much of De Gea with a back pass against Villa, for example.

Although Maguire's partnership with Varane was viewed as one of the best in the Premier League ahead of the new season, Maguire has underwhelmed and is perhaps suffering from a Euro 2020 hangover - so is it time for Solskjaer to play Victor Lindelof instead?

There have been two constants that have defined Solskjaer's tenure at United and they are the Norwegian's persistence with the 4-2-3-1 formation and his unwavering trust in Maguire, which suggests he won't be dropped despite his poor form anytime soon.

It's clear that Maguire is enduring a rough patch, though, and Varane is yet to enjoy the full potential of the pair's partnership.

Varane regularly played alongside Sergio Ramos at Real Madrid, which was the foundation for the Spanish giant's recent trophy-laden years, and the Frenchman has made his desire to win silverware at United no secret since he swapped Madrid for Manchester.

But if United want to win a trophy this season, it's imperative that Maguire's form next to Varane improves.