MELBOURNE defender Heritier Lumumba is disputing the way the club handled his concussion in 2016 and may have played his last game for the Demons. 

However, the club has asked for restraint as it works through issues associated with the defender's health. 

The 30-year-old missed the start of pre-season training as he seeks further advice on issues relating to concussion that forced him to miss all but one game from round six, 2016.

Fairfax Media revealed on Wednesday night Lumumba was also in discussions with the club about his contract, and his potential entitlements if his career with the club ends. 

He is contracted until the end of 2017 but looks unlikely to trigger an extra year on his contract given he has played just 24 games in two seasons.

But football manager Josh Mahoney said Lumumba was not threatening to sue the Demons, with dialogue between the player and club continuing.

"Heritier and the club are currently investigating issues associated with Heritier's health, to determine his ongoing playing future with the club," Mahoney said.

"Contrary to media reports, Heritier has not threatened legal action against the club.

"We ask media to refrain from further speculation on Heritier's health while he seeks the necessary information to make an informed decision on his playing career."

Lumumba is disputing the way the club handled his concussion in 2016, and may have played his last game for the Demons.

No longer handled by his previous manager, the 30-year-old is understood to have engaged a lawyer to discuss with the club how missing games with concussion may have affected his capacity to trigger a contract clause that would have extended his current agreement into a fourth year in 2018.

Lumumba is understood to be of the view there were times he could have played last year, although the Demons are comfortable with their management of his concussion.

In revealing the situation, Fairfax Media reported on Wednesday night that Melbourne had approached the AFLPA to assist the club with negotiations.

New coach Simon Goodwin said a fortnight ago Lumumba had passed all the tests relating to his concussion and he expected him to begin training on November 21.

However Lumumba failed to appear on the track on Monday, with football manager Josh Mahoney revealing the Collingwood premiership defender was seeking further information about his concussion.

"We have been very diligent with our concussion management and we are supportive of Heritier gathering this information," Mahoney said.

Lumumba was All Australian in Collingwood's 2010 premiership year as a running defender and has played 223 games after arriving at the Magpies as a rookie.