SAM Blease has detailed the lingering memory loss, mood changes and headaches that came from a delayed concussion that has ended his football career.

The 24-year-old Geelong midfielder this week announced his retirement, which will stop him from playing at any level again.

Blease says a seemingly innocuous head knock in a VFL game on July 25 eventually led to weeks of symptoms, which forced doctors to advise him not to risk playing again.

“I had some pretty significant symptoms for a long period of time, which hung around for five to six weeks,” he said.

“I couldn’t run for two or three weeks without getting headaches; and I was quite flat, (whereas) I’m quite a happy person on the best of days, so having two or three weeks where I was really down and out made me really have a really good hard think about it, and put it all into perspective.

“I couldn’t sleep at night, and memory loss, just simple things that are easy to do, I wasn’t doing so well, and that was a bit of a concern from the doctor’s point of view.

“Just short-term (memory loss), just like going to your car without your keys, and leaving your wallet somewhere and stuff like that that I generally don’t do.”

Blease said he passed a concussion test during the game, but it was the next day he started to notice something wasn’t quite right.

“I got just a flying elbow to the head, it split me open, I got about six or seven stitches in my head. I’ve been split open a few times before and thought it was just something like that,” he said.

“I did all the concussion stuff that we usually do, just the normal concussion protocols, and I passed all of that, and was fit to go back on, but in saying that, on reflection, when I watch back the game, I didn’t get much of the footy in the second half ... so it probably did have some impact on how I was performing.

“I just forgot bits and pieces from the game the following day. I went out for dinner that night and felt OK, just had a bit of a headache but didn’t think anything untoward.

“I remember starting the game well but I can’t remember much of the second half after I came back out, which is probably a little bit concerning, considering I’d only played 24 hours earlier.”

Blease said after consulting neurologists and getting second and third opinions, the decision was left in his hands.

“Once the doctors were insinuating that it’s probably not a great idea for me to continue to keep playing, I just needed to think more about the long-term stuff and the effects it might have, not today or tomorrow or the next day, it’s more five to 10, 15 years down the track, what does that look like for me then?” he said.

Blease, who played 33 games over four years at Melbourne and just one at Geelong this season, said he was still suffering some memory loss and headaches after exercising, almost six weeks after the incident.

It was his second major concussion of the year, after being injured in a training drill earlier in the year.

“I copped a really significant one in the pre-season, just got tackled at training, got slung around like a sling tackle, that put me out for three weeks; and then this other one was a really significant one again. These two this year were probably the main ones I’ve had,” he said.

Blease was out of contract at the end of the season but, despite believing he’d had a good year in the VFL, said after missing a third of the season “you’ve probably got your back up against it” to be re-signed.

Even though it didn’t work out as planned, he said he had loved every second of his time at Geelong.

“It’s just such a great football club. That’s probably the side I’m going to barrack for and I’ve only been there a year,” he said.

He hopes to keep his connection to football going by returning in some capacity to his junior club Norwood in the Eastern Football Club in Melbourne.