Membrey, without a senior game in his first season, was the standout forward for the Swans in their 12.9 (81) to 10.13 (73) loss at the north Brisbane suburb of Aspley.
The 19-year-old kicked two goals in an even first-half, then two more to give the Swans a third quarter lead with a combination of strong leading and overhead marking.
The Swans seniors play Fremantle in Perth tonight with the winner to play Hawthorn in next Saturday's Grand Final.
Membrey could come into calculations if the Swans win and regular spearhead Kurt Tippett – who is missing the Dockers clash – does not overcome strained ligaments in his leg.
Tony Armstrong also played well, although he slightly faded on a hot Brisbane afternoon.
Young Lion Jesse O'Brien won the Andrew Ireland Medal as best player afield.
Rookie forward Michael Close kicked three goals.
Twitter: @AFL_mikewhiting
