A tighthead prop, Issac came on to the scene in 2017 with a stand out season for his Nelson club, his form earning him a Mako call up as an injury replacement and six caps. His promise lead to a 2018 Blues contract but injury prevented him taking the field. He had a strong 2019 Mitre 10 Cup campaign making 11 appearances including off the bench in the victorious Premiership team.