Former wonderkid Freddy Adu has opened up on his trial at Manchester United – revealing his adulation for Sir Alex Ferguson and the advice given to him by Cristiano Ronaldo.

Adu spent a fortnight in Manchester at the age of 16 after being earmarked as the most exciting young talent in world football.

The American ace made his debut in the MLS at the age of just 14 for DC United.

But work permit issues scuppered any hope of a move to the Premier League after his trial, with Adu returning to America where his career faded into obscurity.

The 32-year-old, who hasn’t played a professional game in over three years, has lifted the lid on his short stint in Manchester and the conversations he had with the likes of Ferguson, Ronaldo, and a host of other United superstars.

“I was there for almost a month and I got to meet everybody like Wayne Rooney – and it was when Manchester United were at the peak of their powers. Cristiano Ronaldo was there at the time and it was when he was becoming the best player in the world. [Paul] Scholes was still there, [Ryan] Giggs was still there – it was amazing!”

And Adu revealed that Ronaldo went out of his way to make the youngster feel welcome during his short stint in Manchester – and even offered the American prodigy some advice.

“Everybody is always talking about Ronaldo is arrogant, he is this and that, but let me tell you that out of all of the players that were there – he was the one person out of all of them that made it a point to come to me, to talk to me, offered to take me to dinner,” Adu added.

“I mean, he was an amazing person. Of course, I already had huge respect for Ronaldo, but after that, I had so much respect for him and he literally became my favourite player just because of the kind of person that he was and what I witnessed.

“We had a little bit of a talk – I mostly trained with the U23s when I was there as I was only 16 years old at the time, but I did get a couple of training sessions in with the first team and it was awesome. We actually played against the first team and I played really well during that game as I was so amped up! It was amazing to be around there, to see the levels they were at.

“At that point I was so young, I had the contract with DC United and The MLS wasn’t ready to let me go anywhere at that point. So we spoke with Manchester United and Sir Alex Ferguson who said he was going to keep an eye on me, and to keep doing what I was doing.”

Adu is adamant that working under Ferguson would have ensured he reached his potential.