Whakaotihia te rerenga e whai ake nei: Kua hoki mai a O'Brien mai i te whara i mua o te tau 2015-16 I whakaatuhia ia mo Connacht i ta raatau tukinga mo Grenoble, a ka tu hei rangatira mo te taha o nga Eagles. I te Whiringa-a-rangi 2015, i whakaingoatia a O'Brien ki te kapa Connacht mo te haerenga ki te taone Siberian o Krasnoyarsk mo te kemu 2015 <unk> 16 Challenge Cup. I timata ia i te 14 o Noema i te keemu ki a Enisey-STM, ka tae mai i muri i nga meneti 58 hei whakakapi mo te rangatira a John Muldoon. I puta tuatahi a O'Brien i te whakataetae i ngā wiki e rua i muri mai i tētahi
2015<unk>16 Pro12 derby ki a Munster, i puta mai i te papa mo Eoghan Masterson i a Connacht i wikitoria i Thomond Park mo te wa tuatahi mai i te 1986. I te marama o Hanuere 2016 i panuitia kua hainatia e O'Brien tetahi kirimana matua me te kirimana, e kite ana ia i a ia hei mema o te roopu katoa mo te tau 2016-17.