For anybody tuning in to see what all the fuss was about regarding the prodigy, the message was clear.

The greatest player of them all was anointing the new boy for greatness.

The only problem with the slick marketing was that Adu was stuck on the bench for the first hour of the match and barely impacted once introduced. A spluttering start to his career set the tone for much of what came after.

Just two and a half years down the line, Adu's star has fallen so far that his recent trial at Manchester United was reckoned by some to be a Nike stunt rather than a genuine evaluation opportunity.

Even if Alex Ferguson made polite noises about his ability, few people in American soccer are taking the United manager's interest at face value. After two lacklustre seasons, Adu only began to look comfortable in Major League Soccer during the campaign just gone. One breathtaking goal against Real Salt Lake apart, he has looked good without being great. A 17-year-old Cristiano Ronaldo he is not.

"He is a wonderful talent, but I worry about his size, " said Alexi Lalas, former American international and current general manager of the Los Angeles Galaxy. "He needs to go to the appropriate team.

If he goes to the wrong team, he will get swallowed up on and off the pitch."

That Adu has failed to live up to the hype was hardly surprising because Pele's arrival at the New York Cosmos in the '70s wasn't attended by the kind of exaggeration and expectation that prefaced Adu coming off the bench for DC United for the first time. From the moment he signed a $1m deal with Nike in 2003, Adu (below) was transformed from promising youngster into media superstar. Ever before kicking a ball professionally, he sat on David Letterman's couch, walked the gauntlet of screaming girls on MTV's Total Request Live (TRL), and was profiled on CBS's current-affairs flagship 60 Minutes.

"It's like Mozart, " said Pele, in a quote that some would argue demonstrates the Brazilian's knack for always saying the right thing once an endorsement deal is on the table. "Mozart started when he was five years old. If you are good, you are good. God gave Freddy the gift to play. If he is prepared mentally and physically, nobody will stop him."

Pele wasn't alone in losing the plot a little. Before he'd finished an accelerated version of high school, The Washington Post had Adu on their front page six times, Vanity Fair and Newsweek subjected him to profiles, and 400 media credentials were issued by DC United for his debut.

Having swapped life in the Ghanaian fishing port of Tema for Potomac, Maryland when his mother won a green card lottery, he'd made such an impact as a 10year-old in schoolboys' soccer that Sports Illustrated embarked on an investigation to prove the veracity of his birth certificate.

Once he started playing in MLS, the questions about his age began to disappear because mostly he looked like a boy against men. At 5ft 7in and just over 10st, he was at a physical disadvantage bouncing off defenders, all of whom knew well that his starting salary of $500,000 was by some distance the largest in the League. Against this background, it was inevitable that DC United's canny coach, Peter Nowak, opted to use Adu sparingly. Too sparingly for the player's liking. Towards the end of the 2005 season, he started to mouth off about the need to play more.

At that point, there was a worrying sense Adu was listening too much to people involved in his marketing and not enough to those trying to improve his undoubted natural talent. That suspicion has gained currency again in recent weeks. The flirtation with United has catapulted him back into the headlines but really, he's nowhere near ready to make the leap to that level. The last time he measured himself in competition outside the MLS, he was found severely wanting.

Having travelled to the 2005 World Under-20 championships with the US expecting to be one of the stars of the tournament in Holland, he failed to impact and returned with a damaged reputation.

It didn't help matters that the performances of Argentina's Lionel Messi and Nigeria's John Obi Mikel put Adu's status as the most talked-about teenager in the game into some context.

United and Adu crossed paths long before he fetched up at Carrington last month.

In the summer of 2003, he travelled to Seattle to watch them play.

"They were walking out on the street afterwards and I was with one of the Nike reps driving along, so he stopped and took me over to introduce me to them, " said Adu. "It was cool, because they actually knew who I was.

There was Van Nistelrooy, Solskjaer, Giggs, Neville. I was like: 'You know who I am? I've been watching you guys for the longest time.'" He may be watching them a little longer yet.