The 22-year-old fighter was today in intensive care after being knocked out by Ukrainian Sergei Devekov in the 10th round of their super-bantamweight fight on Saturday night.

Roy Weller, a leading expert in head injuries and professor of neuropathology at Southampton general hospital said: ``it will probably take (48 hours) for the swelling to reduce, allowing doctors to get a better idea of his chances for recovery.

Oliver was being kept unconscious by doctors as the national hospital for neurology and neurosurgery in Bloomsbury, central London, where he underwent three hours of emergency surgery for a brain clot.