Sustaining an injury before the 2014 season, Stirzaker only played eight of the sixteen games, starting in just four. After a fairly successful 2015 season for Stirzaker – playing fifteen games, scoring three tries, and helped lead the Rebels to a tenth position – he was among rumours of a possible call up to the Wallabies squad. Stirzaker is eligible to represent three countries internationally. Australia, England, and South Africa.