Complex sentence: He was going to moved to Queensland but instead moved to South Australia where he played for the Port Adelaide Magpies in the SANFL for the commencement of the 1973 season, playing 70-odd games before his premature retirement due to a knee injury.
Split into simpler sentences: He was going to move to Queensland but instead moved to South Australia where he played for the Port Adelaide Magpies in the SANFL. He made his SANFL debut in the 1973 season, playing approximately 70 games before his premature retirement due to a knee injury.