Versatile but reliable, Warwick came to the fore on the European stage after switching from Connacht to Munster in 2006. He previously represented Manly in Australia and also graduated through the ranks to represent his country at Sevens level, an eventuality that would later prevent him becoming available for Ireland in international rugby. In 2009, Warwick agreed a deal with London Irish but turned his back on the move to re-sign in Limerick. In November 2010 he kicked Munster to a famous victory over Australia at Thomond Park but announced a month later his intentions to leave at the end of the season, joining Stade Francais.