TWO-TIME premiership ruckman Darren Jolly was left shocked and scared after a persistent headache he had been suffering from turned out to be a brain tumour.

Jolly, who won flags with Sydney and Collingwood, visited a doctor after a common headache would not abate for three consecutive days.

An MRI scan revealed a lump, with the 33-year-old undergoing surgery to remove the tumour and drain excess fluid from his brain.

"I knew the radiologist from footy days," Jolly said.

"He said 'listen, we need to go have an MRI straight away, there's something there and we need to know what it is'.

"I had an MRI ... he came to me and said `you need to go and see a specialist, you've got a lump on your brain'.

"The list of possible things that can go wrong (with surgery) was a bit of a worry .. loss of memory, death, paralysis, seizures.

"I'm only 33, that (death) was nowhere near the radar of things I had to worry about.

"It was very scary to hear all of that when it's so sudden."

Specialists told Jolly the benign cyst was unrelated to any head knocks he suffered during a 237-game career with Melbourne, Sydney and Collingwood.

"No relation whatsoever between this and footy," he said.

"It's just a freaky occurrence."

Jolly told the Nine Network he learned the tumour had been there for a "long time".