Former Parramatta forward Brett Horsnell is taking legal action against the club over mental health issues he has suffered following his rugby league career.

The landmark case, which is scheduled to begin in the Supreme Court this month, has the potential to have huge ramifications for Australian sport and could result in more actions being taken against sporting clubs and bodies.

Final season: Brett Horsnell, in Parramatta colours, in a 1998 clash with North Queensland. Credit:NRL Photos

The action comes just months after Fairfax Media revealed former NSW State of Origin winger James McManus was taking legal action against Newcastle over the club's handling of his concussions.

Horsnell made 154 first-grade appearances during a distinguished career for the Gold Coast Giants, South Queensland Crushers and the Eels. He played for the blue and golds for two years, including his final season of professional football in 1998. The Giants and Crushers have long since disappeared from the rugby league landscape, leaving the Eels as the only body left for him to sue after suffering a series of health problems in post-football life.