O'Brien also assumed a part-time coaching role while at the club and considers the time spent in Australia as some of the most vital parts of his career.

In the same year, he joined the Essel Group's Indian Cricket League (ICL) to represent the Delhi Jets team for one season.

[9] At the end of the 2008 season, O'Brien was named Northamptonshire's player of the year and was rewarded for his consistent performances with a three-year contract with the club.

[11] 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.

[12] In 2012, O'Brien signed a contract worth $80,000 with Khulna Royal Bengals represent them in the newly formed Bangladesh Premier League, a domestic t20 competition.

O'Brien was selected in Ireland's 15-man squad for the 2011 World Cup to be hosted by Bangladesh, India, and Sri Lanka between February and April.

In the same match, O'Brien and Porterfield established a new records for Ireland's third wicket in ODI, putting on 113 runs together.

[23] Ireland were due to play two ODIs against Pakistan in May, however O'Brien suffered an injury to his hand and was forced to miss the fixtures.

[24] On 16 February 2015, he smashed unbeaten 79 runs off 60 balls with 11 fours, guided Ireland to the victory against another Test match playing nations, the West Indies.

O'Brien's score was helped to beat mighty West Indian pace attack and finally Irish won their first match of 2015 ICC Cricket World Cup.