She told St Kilda's website today that she had been suffering from months after a routine blow to the head in pre-season training earlier this year.

After a break from the game, she bounced back in time for the season kick off - but just weeks later, she got pole-axed by another bout of concussion mid game...without apparently suffering any blow to the head.

“It started in about March at the start of this year,” Walker told saints.com.au.

“I just copped a knock at training, a shoulder to the eye, and I was out for about two months.

“I’ve had history with ongoing concussions, so I had a month of rehab with neuro specialists and neuro rehab physios, and then I got cleared for Round 1, and was getting better physically and mentally.”

But she revealed in the round nine game, her world came tumbling down.

“I had a knock just before half-time and came off, and I don’t remember what happened,” Walker said.

“I felt really dizzy and nauseous, had all the symptoms, but I don’t remember getting hit in the head – no-one saw me getting hit in the head, and you couldn’t see in the vision either that I got hit in the head.

“It was the ninth concussion in about six or seven years that I’d had, so I’ve had a few.

“As a result, speaking to doctors and family and friends, I’ve just had to pull the pin, which is unfortunate being so young.

"It’s something you don’t want to have to hear, when I’m so close to getting to the big league and suddenly having to stop, it was a really hard thing to take.”

Walker is now working as a receptionist for the Saints at their base while also defensive line coach for the Southern Stars.

She added: “When I come here to see the girls, it’s pretty hard because I’m not allowed to train in case I get concussed again.

“Because of an injury I can’t really see, I can’t grow what I’ve helped to build and create over the last 14 months, and even on gamedays, when I’m not a part of that, it really hurts.

“A 19-year-old shouldn’t have to retire.”