Crocker, 33, made his first grade debut for Sydney Roosters back in 2001, and went on to win the 2002 premiership and appear in their 2003 and 2004 Grand Final teams.
He then moved to Melbourne for three seasons, winning the 2007 NRL Grand Final, before going to Souths, where he has made 68 appearances.
Crocker said: “After undergoing surgery in April my focus has been to get back on the field. My goal was to captain South Sydney to a grand final win and to play again next season.
“It has been a challenging year and I have explored every possible option to get myself back playing. Unfortunately, I have arrived at the point where my knee is unable to meet the demands of professional football.
“Sadly this means I will be unable to play for the South Sydney Rabbitohs for the remainder of this season.
“It has been an incredible 13 years playing in the NRL and my career has been blessed.
“I would like to take this opportunity to thank everybody involved in my Rugby League career.”