Switching from football to rugby, he played at underage level for Leinster and Ireland, and spent four seasons with Leinster.
Munster
Ronan moved to Munster in 2007, and made his debut against Scarlets in September of that year.[1] He was in the Munster team that beat Leinster to win the 2011 Magners League Grand Final.[2]
A knee injury sustained in Munster's Heineken Cup Round 5 clash with Castres Olympique ruled Ronan out for the rest of the 2011–12 season.[3] He signed a new two-year contract with Munster in March 2012.[4]
Ronan earned his 100th cap for Munster on 3 May 2013, coming on against Zebre in a Pro12 fixture. On 30 April 2014, it was announced that Ronan was retiring from rugby due to a knee injury sustained in October 2013.[5]
Ireland
Ronan made his debut for Ireland against Canada on 23 May 2009,[6] starting and finishing the match in a 25–6 win. He earned his second cap a week later against the USA. He was called up to the squad for the 2010 Summer Tour as a replacement for Kevin McLaughlin and played against the Barbarians, New Zealand Māori and Australia.[7]