Beau Maister announces his immediate retirement after 44 games in six seasons at the top level.
Maister's season was ended three weeks ago by a shoulder injury that required surgery and he told his teammates of his decision on Tuesday morning.
"It is with real disappointment that we say goodbye to Beau as he has become one of the most admired and respected players within our group," St Kilda head of football Chris Pelchen said.
"Since joining the Saints, he has performed to his absolute ability through sheer hard work and determination … qualities that have endeared him to everyone at the club.
"We thank Beau for his commitment to the Saints and wish him every success for the future."