 On October 6, 2014, O'Brien was successful in earning a one-year, two-way contract with the Panthers.On July 16, 2015, O'Brien signed as a free agent to a one-year, two-way contract in a return his original NHL club, the Anaheim Ducks.Unable to make the Ducks roster out of training camp, O'Brien added a veteran presence to AHL affiliate, the San Diego Gulls, for the duration of the 2015–16 season, posting 1 goal and 17 points in 57 games.