His name was once on the back of millions of United shirts but David Beckham has proved he's still one of the fans – by popping into the club shop to BUY a jersey.

The legend was spotted by astonished supporters at the Old Trafford Megastore on Monday afternoon – with many of them so stunned to see him that they had to do a double take.

He was back at the club 22 years to the day after he signed for them as a trainee – and former team-mates Paul Scholes and Gary Neville were also seen at the stadium.

The trio joined United as fresh-faced teenagers on July 8, 1991, and went on to become all-time greats.

Their appearance was the talk of Twitter with United journalist Nick Coppack even posting of his surprise on the site.

He wrote: “Popped to the Megastore to buy a home shirt for a friend and David Beckham is in there, doing the same. #unexpected.”

Beckham's luxury Bentley Continental car was pictured outside the store and pictures on Twitter showed him laden with bags – and being mobbed by excited fans.

He was also captured on camera picking up next season's new home shirt – with 'Champions 20' printed on the back of it.

Another fan, Kenny Smith, who spotted him in the shop, posted a picture of him on Twitter with the caption: “Utd legend #becks”.

There was no official word on the reason for his flying visit – but in May, we reported that United were believed to be trying to lure the former England captain back to Old Trafford after he announced his retirement from football.

The 38-year-old has always retained strong ties with United, despite going on to play for Real Madrid, LA Galaxy, AC Milan and Paris St Germain.

And he revealed as recently as last November that he one day expected to become an ambassador at United, saying: “I’m sure that will happen in some way.”