The 33-year-old sustained the injury during a SANFL trial match on Thursday, with the club unable to confirm a likely return date for the veteran.
“We’re disappointed for Tyson,” Port Adelaide football boss Chris Davies said.
“His injury means he will miss a period of time at the start of the SANFL season but that won’t affect his value to the group.”
Goldsack joined the Power via the Rookie Draft in December last year, 12 months on from deciding to retire after 165 games with Collingwood.
The seasoned veteran was acquired to add a wealth of experience to Ken Hinkley’s backline and will be eyeing a return to AFL level later in 2021.