Sidelined veteran player Liam Picken on Tuesday outlined his battles with post-concussion syndrome following previous head trauma in March, saying he is unclear when he will return to the AFL.

Picken, who hasn’t played since pre-season, posted an emotional Twitter thread on Tuesday regarding his ongoing battle with the syndrome following a string of concussions.

“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”, he said.

“Concussion is an extremely complex injury with so many unknowns. It’s also an injury that not many people understand.

Coach Luke Beveridge in April speculated Picken — who is set to play until next season —may miss it entirely, ruled out for an indefinite time period.

“Although it’s been made clear to me that I’m on the road to full health, the timeline is unclear,”  Picken said in regards to his recovery, which he claimed has had more complications than most.

“A small minority don’t recover from concussion as quickly and have a longer road to recovery. Those people are usually diagnosed with post-concussion syndrome, like me,” he said.

Picken encouraged concussion-sufferers to “speak up and seek help” in appreciation for the guidance he received during his experience with the injury.

“Hopefully my transparency has helped others that may be feeling alone in their journey.”

Picken suffered the injury during the JLT Community Series, and has not featured for the Dogs this season.