The duo suffered respective ankle and foot injuries against the Demons last week and although the club was hopeful the pair would get through a fitness test on Friday, both were deemed unfit to play the Saints.
It means Sam Gray and Ben Newton will return to the side, while John Butcher and Cam O'Shea will join Jake Neade as emergencies for the game.
Port Adelaide plays St Kilda at the Adelaide Oval on Saturday afternoon at 4:10pm.