Former Manly Sea Eagles forward Lloyd Perrett has launched a lawsuit against the club over a training session in 2017.

The Sydney Morning Herald is reporting that the forward is claiming a training session held left him in a comatose state for two days, and that he has never recovered from it.

The alleged career-ending event, which occurred early in the 2017 pre-season, saw Perrett forced to run three two-kilometre time trials without water or other fluids provided.

That was, allegedly, a directive from club staff to complete the session without water, and he was taken to hospital in what has been described as a 'comatose state' after collapsing during the third time trial.

It's understood Perrett suffered from severe heat stroke, leaving him in a comatose state for two days, and that he suffered a seizure, poor heat tolerance, severe pain, fatigue, muscular degeneration, impaired cognitive ability, anxiety, moodiness and poor kidney, liver and thyroid function as a result of the incident.

Perrett attempted a comeback ahead of 2018, and at one point suffered heat stroke again during pre-season training, having to be taken back to the hospital.

A former junior Origin and Australian player, Perrett managed to play 13 games during 2018, but only averaged 18 minutes per game, with the claim alleging Perrett was in severe pain during those games.

Perrett was eventually released from Manly at the end of 2019 after just three more games, and he signed a train and trial deal with the Broncos, but never proceeded with the club.

His last NRL game came at the age of 24, with the forward retiring just 56 games into his career.