Beckham revealed as an asthma sufferer

Beckham's AC Milan team could be drawn to play United on Friday (GETTY IMAGES)

David Beckham's agent has admitted the 34-year-old has been an asthma sufferer for years - but insists it has not hampered the player's performance.

Beckham was pictured using an inhaler during LA Galaxy's MLS Cup final defeat to Real Salt Lake and Simon Oliveira admitted to the Daily Mail: "David has suffered with this since he was a young boy but it has obviously had no effect on his performance.

"He has never sought to make it public but if it does inspire any sufferer to think they can achieve great things like many other sportsmen have done then so much the better."

The Galaxy lost a penalty shoot-out after England midfielder Beckham had played the full 120 minutes. He is due to report for training with AC Milan on December 28.