 In a tour match against Australia during the 2009 Ashes in July 2009, O'Brien made scores of 30 and 58 in a match Northamptonshire lost.During his half century, he scored seven boundaries off the struggling Mitchell Johnson.O'Brien missed most of the 2010 season after undergoing finger surgery in July; in his absence, David Murphy was Northamptonshire's first-choice wicket-keeper.