NORTH Melbourne hard nut Leigh Adams has suffered yet another head knock while playing for VFL affiliate Werribee on Sunday.

The 27-year-old received a suspected knee to the back of his head in the third quarter of the Tigers' clash against Collingwood at Victoria Park.

The Roos midfielder was able to get up and continue playing after the incident but was taken off the ground shortly afterwards.

Adams took several weeks to consider his future in the game after suffering a head knock in a VFL practice match in March, having sustained three concussions in 2014.

North Melbourne development manager Ben Dyer said Adams was assessed after the collision and did not take any further part in the match.

"He was taken off, more than anything else, for precautionary reasons," Dyer told on Sunday.

"He was checked out by the doctors and they elected to not put him back out there." 

Dyer said the club medicos would monitor Adams on Sunday afternoon, with the severity of his latest knock unknown at this stage. 

Werribee's clash against the Magpies was Adams' third straight VFL appearance after overcoming a concussion he sustained in a practice match against Footscray in March.

There had been speculation Adams was contemplating retiring from the game because of concerns about the long-term effects of repeated concussion.

On Saturday, he opened up about the short-term depression he faced after his recent concussion against the Bulldogs in the VFL.

"I just thought the world was against me and, 'Poor me … I don't want to play any more'," Adams told Channel Seven.

"It is really common, one in two people with concussion get depression."

Adams has endured several heavy collisions during his 104-game career, including knocks in round 12, round 18 and round 23 last year, with the latter sidelining him from the Roos' three finals.