It's been a quarter of a century since Ramon Calliste, then just 15, joined Manchester United. The young Welsh forward was already being likened to his compatriot Ryan Giggs, but that didn't stop him leaving to join Liverpool.

Sir Alex Ferguson had brought Calliste to Old Trafford where he trained with club legends such as David Beckham, Wayne Rooney and Cristiano Ronaldo. He even made it onto the list of the top 100 young players in world football shortly after signing his contract.

The Cardiff-born prodigy had high expectations placed upon him. Despite winning the FA Youth Cup in 2003, his career didn't take off in Manchester and he was released in 2005 without ever making an appearance for the senior team.

In an unusual move, the then-19 year old joined arch-rivals Liverpool shortly after leaving...