Due to his performance at the 2007 FIFA U-17 World Cup, Bojan looked destined for the top after breaking into the Barcelona first team for whom he made 104 appearances and scored 26 goals.
Stints at Roma, AC Milan, Ajax, Stoke City, Mainz and Alaves followed but the Spanish striker failed to impress and left Europe for Canada, joining Montreal Impact as a 28-year old.
The 31-year old ex-Spanish international now plays in Japan for Vissel Kobe.
Belgium international, Adnan Januzaj has been with Spanish club, Real Sociedad for the past five years which suggests that the 27-year old is having a decent career.
But just under a decade ago, right at the start of the post-Fergie era, 18-year old Januzaj was widely expected to be the next Ryan Giggs at Old Trafford.
Of those targets, he was completely wide off the mark and after two unsuccessful loan spells at Borussia Dortmund and Sunderland, he wound up at Sociedad where he appears to have found a home as an average player at best.
Italian striker Giuseppe Rossi was snapped up by Manchester United as a 17-year old with a big future, he even scored on his debut to further heighten expectations.
Rossi found playing time hard to come by at Old Trafford and after a failed loan to Newcastle, he went on another loan to Parma to remind the world what he was capable of.
After leaving Manchester United, Rossi went to Villarreal and then Fiorentina and spent a combined decade at these clubs, averaging just 17 games per year due to injuries.
The 35-year old now plays for SPAL in the Italian second division after a stint in the United States.
A typical example of how quickly things can go wrong, Hachim Mastour had the world at his feet as a teenager for AC Milan and made his Morocco national team debut aged 16, making him the nation’s youngest debutant.
From making it into the Milan first-team at 14 years old to now being a 23-year old free agent who last played in the Italian third division, Mastour's case is a sorry one.
14-year old Freddy Adu became the youngest player to sign a professional contract and play in a professional game in all American sports all the way back in 2004 when he was drafted by D.C United.
He soon became the youngest goalscorer in MLS history and was a work permit away from joining Manchester United.
That move never materialised but Adu soon got his European transfer with a move worth $2 million but that didn’t work out and the former prodigy was sent out on multiple failed loan spells.
The 32-year old is now without a club and ruing the effects of perhaps starting too early.