After consecutive lean seasons for his native New South Wales, Aaron O'Brien signed with South Australia for 2008-09 and the fresh start reignited a promising career. His move west was rewarded with his most consistent season in years. He managed 392 runs in nine Sheffield Shield matches - though a top score of 63 was disappointing - as well as appearances in all one-day games. In 2009-10 he averaged around 30 with the bat in the Sheffield Shield and FR Cup, and while his 14 first-class wickets came at 63, he was more effective in the 50-over format with 12 at 31. His seven Twenty20 victims came every 9.14 runs.

Before switching to the Redbacks, his summer had consisted of only three Twenty20 outings for the Blues, which was well down on his five Pura Cup games and five one-dayers in 2006-07. He was unlucky to be dropped from the limited-overs team after opening that campaign with two half-centuries and he finished with 171 runs at 42.75. His first-class form was weaker and he made 195 runs at 19.5. The previous year, in 2005-06, he had started to turn potential into results as a middle-order batsman and left-arm orthodox spinner.

O'Brien's first game for New South Wales came in 2001-02 and he played matches in four consecutive seasons without securing a consistent berth. He missed only one contest for the Blues in 2005-06 as he scored 468 runs at 36 in the Pura Cup - the outstanding effort was 147 in the win over Western Australia, still his sole first-class hundred - and another 277 at 39.57 to finish in third place on the state's one-day list. His bowling returns have been modest but he has been dangerous and economical in the Twenty20 format.
Cricinfo staff September 2010