In 2005, Primus made another return to the AFL. His form was not indicative of the Primus of old, however, and it seemed Port were playing Primus out of respect that he was the captain. Not only that, but Port Adelaide were not the same strong side they were just a year earlier. While they eventually had a few results go their way and managed to scrape into the finals, Primus injured his knee again in the final round of the home-and-away season. He was expected to miss only the finals series at first, but later scans revealed that he would require a third knee reconstruction. The likelihood that he would not be able to play until 2007 meant Primus announced his retirement from the AFL at the age of 30.