Signed by the Rowdies on March 30, 2012 to a two-year contract, which includes one year guaranteed and a one-year club option. O'Brien, who hails from Minneapolis, joined the team as a trialist this preseason.
O'Brien played collegiately at Coastal Carolina and the University of Wisconsin-Green Bay. He has seen action for several professional teams, including the Minnesota Thunder in 2008 and 2009 as well as overseas for two clubs in New Zealand.
Has played in five regular season games for 32 minutes... Made Rowdies debut at Atlanta (4.21).