Ronan first came to prominence on the inter-county scene as a dual player in the late 1990s. In 1998 he was a key member of the Cork minor hurling team that reached the provincial decider. Clare provided the opposition on that occasion, however, they proved no match for a superior Cork side. A 3–13 to 0–8 trouncing gave Curran a Munster minor hurling winners' medal. Cork later qualified for the All-Ireland final against arch-rivals Kilkenny with Curran lining out at centre-back. The game proved to be an easy one for the young 'Rebels', as Cork won by 2–15 to 1–9. It was Curran's first All-Ireland winners' medal in the minor hurling grade.