The St Loman's[2] clubman represented University College Dublin in the Sigerson Cup and Westmeath at all levels and starred as Westmeath reached the Leinster Under-21 Football Championship final.
He also played in two games of the 2011 All-Ireland Senior Football Championship and went on to become a permanent fixture in the Westmeath team.
Heslin scored 1–9 in the 2015 Leinster Senior Football Championship semi-final vctory over Meath, his team winning the game despite having to make up 11 points and not having beaten Meath for a long time.
[4] In the 2022 Tailteann Cup final he overtook Dessie Dolan as Westmeath's all-time championship top scorer.
[6][7][8][9] After only three months on the Tigers' rookie list, homesickness proved too much for the St Loman's clubman, and he resumed his inter-county career with Westmeath.