Melbourne defender Heritier Lumumba is set to retire from football amid threats of legal action over his treatment for concussion.

Lumumba is understood to have claimed that doctors stopped him from playing last year due to concussion when he felt he was fit to play and so blocked him from being able to play sufficient games to trigger a clause in his contract for a fourth season with the Demons.

Potential legal action: Heritier Lumumba. Credit:Getty Images

Lumumba did not play a senior game after round six this year, playing only one more game in the VFL for Casey where he suffered another head knock which effectively ended his season.

Now as he enters the third year of his contract, Lumumba cannot play enough games to automatically trigger that fourth year and he is considering legal action over the way he was handled.