The vast majority of football fans expected Alexis Sanchez to be a game-changing signing for Manchester United.The Chilean forward, who was also wanted by Pep Guardiola at Manchester City towards the end of his spell with Arsenal, was widely regarded as one of the Premier League’s best attacking players this time last year and rightly so.United didn’t pay Arsenal a transfer fee - they agreed a deal which saw Henrikh Mkhitaryan move in the opposite direction - but they were still required to cough up astronomical sums of cash in order to secure Sanchez’s signature.Per the Daily Mail, the South American currently earns an eye-watering £391,000-a-week at Old Trafford, plus an additional £75,000 for every start he makes.He was also handed a cool £6.7 million signing-on fee, on top of all that.Almost 12 months later, though, and it’s not unfair to say that Sanchez has been an unmitigated disaster of a signing for the Red Devils.In 30 appearances for the Premier League giants, Sanchez has managed to score just four goals.He’s looked a shadow of the world-class player who lit up the Emirates Stadium for three-and-a-half seasons, leading to fears that his best years are now firmly behind him.However, some United fans believe the departure of Jose Mourinho - who Sanchez did not see eye-to-eye with, according to reports - could be the turning point in his spell at Old Trafford.The Chilean has been out of action for several weeks with a hamstring injury but is now back in training.Sanchez posted a video on his Instagram story of himself working hard in training, complete with ‘Eye of the Tiger’ playing in the background.However, The Sun’s Neil Custis posted has posted a scathing tweet after seeing the footage, branding Sanchez a “disgrace” in a rather eyebrow-raising social media post.“Disgrace, biggest waste of money in Man Utd’s history,” Custis tweeted. “Do not cheer him on to the pitch when he finally decides he is ready to play again.”

As you can probably imagine, Custis’ tweet has sparked a massive response from United fans…

For those unaware, there’s already been some beef between Custis and Sanchez this month.

Custis ran a back-page splash in The Sun claiming Sanchez bet Marcos Rojo £20,000 that Mourinho would be sacked.

According to the report, Sanchez messaged the United players’ WhatsApp group saying: “I told you so!! Patience is all it takes. Rojo you owe me £20k.”

Sanchez called the news ‘false’, insisting he only has ‘gratitude’ for Mourinho.

This infuriated Custis, who added: “Believe what you wish on Sanchez, the story is right. He gives himself away by saying he has gratitude for Mourinho when he actually behaved appallingly towards him.

“Sanchez behaved appallingly to Mourinho to clarify and kept moaning to teammates about how much better things could have been at City.”