Melbourne premiership defender Christian Salem has been sidelined with an ongoing illness related to his thyroid gland.
The 27-year-old speedster was on light duties at the Demons' training session on Monday and won't resume full training until the issue has been resolved.
Club medical staff have not put a timeline on Salem's return to action, putting him in doubt for Melbourne's season opener against the Western Bulldogs on March 18.
Salem has battled a similar issue in the past, with the illness impacting his heart rate, blood pressure, body temperature and weight.
The 143-game defender lost six kilograms due to the thyroid issue soon after being drafted in late 2013.
And in 2016, his resting heart rate at one stage rocketed to around three times the normal level.
Salem has been working with a specialist and the club's medical team to help him recovery from the latest setback.
"Christian is currently undergoing treatment for an illness (related) to his thyroid gland," Demons head of medical Dr Laura Lallanec said.
"Christian has had a similar issue in the past where his thyroid becomes overactive.
"He will continue to be monitored closely by his specialist and reintegrate into training as his thyroid levels stabilise."
Salem was an integral part of Melbourne's drought-breaking 2021 premiership side but was restricted by a knee injury early last season.
He played 13 games in 2022, including losing finals against Sydney and Brisbane that ended the Demons' flag defence.
