 For 2015, Jamieson was included in the squad for their season in the Group A of the 2015 Under-21 Provincial Championship, their first season at that level after winning promotion from Group B at the end of 2014.The team struggled to adjust at this level, winning just one of their twelve matches during the season to finish bottom of the log, but Jamieson once again established himself as a regular in the side, making ten starts and appearing as a replacement in their other two matches.At the start of 2016, Jamieson was included in the squad that participated in the 2016 Varsity Cup tournament.