The NRL has approved the medical retirement of Tim Glasby on the basis of repeated concussions.
Glasby was informed by the NRL that his retirement on medical grounds was accepted last week after his case was assessed.
Glasby played 138 games for Melbourne and Newcastle and was a member of the 2017 Storm premiership team.
There were concerns about his health in July after he suffered ongoing concussion symptoms from repeated head knocks.
As a result, Glasby underwent a series of neurological tests.
Last year, the 31-year-old was stood down for a game after suffering two head knocks in three weeks.
It is understood he is comfortable with the decision to retire and the Knights informed the NRL of their request to formally apply for medical retirement.