Buuxi weedha soo socota: O'Brien wuxuu ka soo laabtay dhaawac ka hor xilli ciyaareedkii 2015-16. Wuxuu u ciyaaray Connacht kulankii horudhaca ee ay la ciyaareen Grenoble, waxaana loo magacaabay kabtanka kooxda Eagles. Bishii Nofeembar 2015, O'Brien waxaa loogu magac daray kooxda Connacht safar loogu tagayo magaalada Siberian ee Krasnoyarsk si loogu ciyaaro 2015 <unk> 16 Challenge Cup. Wuxuu sameeyay kulankiisii ugu horeeyay ee 14 Nofeembar ciyaartii ka dhanka ahayd Enisey-STM, isagoo soo galay 58 daqiiqo kadib isagoo badalay kabtanka John Muldoon. O'Brien ayaa kulankiisii ugu horeeyay ka soo muuqday labo isbuuc ka dib
2015<unk>16 Pro12 derby ka dhanka ah Munster, oo ka soo baxay kursiga keydka Eoghan Masterson markii Connacht uu ku guuleystay Thomond Park markii ugu horreysay tan iyo 1986. Bishii Janaayo 2016 waxaa lagu dhawaaqay in O'Brien uu saxiixay qandaraas qandaraasle ah, kaas oo u arkaa inuu xubin ka noqdo kooxda buuxda ee xilli ciyaareedka 2016-17.