LOS ANGELES -- Wherever possible, Manchester United have tried to keep Mason Greenwood under wraps. It is club policy that youth team players under the age of 18 are not allowed to speak to the media, and even official channels, in-house television station MUTV and the United website, are only rarely granted special access.

United have been especially careful with Greenwood, similar to the way Sir Alex Ferguson shielded Ryan Giggs nearly 30 years ago. The problem, though (if you can call it that) is Greenwood has done more than enough talking on the pitch. So much so, in fact, that Jose Mourinho has taken the 16-year-old to the United States for this summer's preseason tour. He's so young that club photographers are not allowed to take pictures of him on his own, only as part of a larger group.

Ultimately, Greenwood has been presented with the opportunity because of the World Cup. The bulk of the first-team squad is on holiday after the tournament in Russia and Mourinho has bolstered his numbers with the best young players. Still, it is an incredible achievement for Greenwood, who won't turn 17 until October, to be asked to train with the likes of Juan Mata and Anthony Martial this summer.

To put it into context, James Wilson, six years older and with three Premier League goals to his name, has been left at home.

The chances are that Greenwood will not feature that much against Club America, San Jose Earthquakes, AC Milan, Liverpool and Real Madrid this summer, if at all, but the fact he is here at all says everything about how much potential United's coaching staff thinks he has.

Greenwood was raised in Wibsey to the southwest of Bradford and was making headlines by the time he was 4 ... only that was for winning a modelling competition. His prize was a £50 shopping voucher.

He comes from a family of athletes. Sister Ashton, 19, is a runner who attends Manchester Metropolitan University on a sport scholarship, splitting her time between the track and a philosophy degree. She has a personal best of 12.7 seconds over 100 metres, although her preferred event is the 400.

Man United are keeping quiet about Mason Greenwood, second from left, but the 16-year-old's inclusion in the preseason squad speaks volumes. John Peters/Man Utd via Getty Images

Mason isn't slow either, and when combined with an ability to score goals with impressive regularity, it makes for a dangerous centre-forward. He has evolved from a link-up man or No. 10 to a central striker, and despite being eligible for the Under-16s last season, he finished the campaign as the Under-18s' top scorer with 17 goals from 17 starts. His goals helped Kieran McKenna's side win the U-18 Premier League North. (Incidentally, McKenna is also with the first team in the U.S. after making the step up to Mourinho's staff following Rui Faria's departure.)

When the U-19s beat Real Madrid 1-0 to win the ICGT tournament in the Netherlands in May, it was Greenwood who scored the winner. He was named player of the tournament despite being the youngest player in the squad.

And yet, Greenwood is more than just a finisher. Sources have told ESPN FC that his technical ability is beyond anything many of United's age-group coaches have ever seen before in a player his age. He can take corners, free kicks and penalties with both feet so well that it's hard to decipher which is his strongest side.

He has already been capped by England's U-17s and was part of the squad for the Algarve Tournament in Portugal earlier this year. Even before Greenwood began training with the first team last week, sources have told ESPN FC he was already being talked about in the senior dressing room.

Players have shown each other videos of his goals and watched training at Carrington to see for themselves how good he is. The story goes that Ferguson would excitedly tell his senior pros to stay behind at The Cliff to watch Giggs train.

Sources have told ESPN FC that United will look to tie Greenwood to a professional contract as soon as he turns 17. Angel Gomes, another promising youngster on the tour, signed his first professional deal in December to ward off interest from Barcelona. Sources have also told ESPN FC some of Europe's heavyweights are beginning to circle around Greenwood. Manchester City were keen to take him to the Etihad Stadium when he was just 14.

Greenwood and Gomes are part of a small group of youngsters that United are particularly excited about. Midfielder James Garner, England U-17 captain, is another along with Dutch winger Tahith Chong and defender Ethan Laird. Garner and Chong are also in the U.S. with the touring preseason squad.

Garner and Greenwood are close friends and current Fortnite champions at the team hotel in Los Angeles. So far, it appears as though there isn't much Greenwood can't do.