Melbourne boss Walker has surgery

The 71-year-old fell off his bike in Melbourne's Royal Botanic Gardens several weeks ago, receiving broken ribs and concussion in the accident. However, he also suffered a hidden brain injury that only came to light more recently.

Speaking to Australian radio station 3AW, Walker said: "I didn't have any headaches but it came to a head last Saturday evening when I was going to the movies with my wife and I tried to do the button up on the shirt.

"My brain was being ignored by my limbs. I couldn't do my buttons up ... Worst of all, I didn't know how to put my tie on."

Medical officials found out that there had been a fluid build-up in Walker's brain, which required an emergency operation.

"They bored a hole in my skull and took the fluid out and I had to lay flat for a number of days," said Walker, who is already up and about and present at Albert Park in the build-up to the Australian Grand Prix.

"I was a tick away from a seizure ... that would have caused all sorts of complications in the brain and some people don't recover."