Western Bulldogs player Liam Picken has revealed the brutal toll of his ongoing concussion problems, saying he is unsure when he will play AFL again.
Picken posted a series of tweets on Tuesday where he described his experience as "a dark and lonely road to travel".
The premiership player has not played since the pre-season, when he suffered a heavy head knock for the second time in less than a year.
"Concussion is an extremely complex injury with so many unknowns. It's also an injury that not many people really understand," the forward said.
"And because it's an injury with symptoms less visible to others unlike breaking a leg etc, it's hard for others to understand what you're going through.
"In fact, it can be a lonely and dark road to travel."
Picken added he was in a small minority of concussion victims who do not recover quickly and usually are diagnosed with post-concussion syndrome.
"I've had a number of hits and concussions, but I knew from the outset that this time was different," he said of his head knock during the pre-season match.
Picken was hurt in an accidental collision with teammate Josh Dunkley.
Bulldogs coach Luke Beveridge said in April that there is a chance Picken might not play this season.
"Some of the symptoms that have impacted me have been light and noise sensitivity, noise ringing in my ears, vision, headaches, migraines, mental wellness, memory function and impaired balance," Picken said.
"Some of these I still have and others I've fully recovered from. I'm hoping it's any day now.
"But one of the hardest aspects of post-concussion syndrome is not knowing when you'll get better.
"People still ask what's going on with me or why I'm not playing yet - and although it's been made clear to me that I'm on the road to full health, the timeline is unclear."
Picken added he feels lucky, because he has had the support of the Bulldogs' club doctors and world experts in the field.
"Knowing I'm in extremely qualified hands has made this journey less daunting and has accelerated my recovery," he said.
Picken also encouraged anyone who has suffered concussion and is not feeling right to seek help.
"Hopefully my transparency has helped others that may be feeling alone in their journey," he said.