At the conclusion of his second contract with the Senators, O'Brien was not offered a new contract and signed his first contract abroad with in the Russian Kontinental Hockey League with Metallurg Novokuznetsk. In the 2014–15 season, O'Brien scored a respectable 12 points in 22 games before he opted for a return to North America and secured a release from Metallurg Novokuznetsk on December 14, 2014. On December 26, 2014, O'Brien signalled a return to the AHL in signing with the Wilkes-Barre/Scranton Penguins. He was then immediately claimed off waivers by the Hershey Bears.