The substance Hird overdosed on is unknown at this time.

He was rushed to Cabrini Hospital via ambulance on Wednesday night.

The AFL Premiership star has had a trying few years and left the Bombers in August 2015 following the club's damaging supplements saga which resulted in a 12 month suspension in August 2013.

He returned to lead the team for the 2015 season but resigned in August due to heavy pressure on and off the field.

Hird failed to have Chubb Insurance cover almost $660,000 of legal bills he amounted while challenging AFL and ASADA in court.

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.

Suicide Call Back Service 1300 659 467.