The Power add Balyn O'Brien and Mitch Zadow to its list as pre-season supplemental selection period (SSP) signings.
"Mitch and Balyn have worked really hard to earn this opportunity," Port list manager Jason Cripps said.
"Mitch is a 21-year-old who we monitored in the back half of last year when his footy with East Fremantle really grew."
"Balyn had a consistent season in the SANFL under 18s and national champs, before breaking into the Norwood league side and holding his place through the finals."