Eckersley, now of Aarhus, played with Real Madrid icons while at United.
"I remember a first-team session at United, eight versus eight. Roy Keane was on my team; Beckham was on theirs. He kept crossing, and they kept scoring from them. I couldn't get near him. Keane was shouting at me, going mad: 'Adam! You've got to get out to him, stop the crosses!'
"I thought: 'The best full backs in the world can't stop him, so what chance do I have!'
"Keane just wanted the best though. I'm a bit like that with the younger players now."