A right-arm medium-pacer whose stock delivery is the out-swinger Kaushalya Weeraratne was earmarked early as an allrounder for the future. His bowling was stronger than his batting during the initial stages but he had the ability to hit the ball cleanly. He was an integral part of Sri Lanka's Under-19 World Cup squad in 2000 and his 12 wickets at an average of 13 apiece help fast track his progress to the senior team. Weeraratne made his ODI debut in the Asia Cup in 2000. However, poor form and injury resulted in Weeraratne failing to cement his place in the team and he spent nearly five years on the sidelines after his 11th ODI in 2003. He forced himself back into reckoning after successfully remodeling his action and scored a blistering half-century off 12 balls, which was the fastest fifty in one-day cricket, during a domestic match in 2005. He received a call up to the national squad for the tour of the West Indies and the Asia Cup in 2008.