Buuxi weedha soo socota: Ka dib markii uu horay ugu soo ciyaaray England U16 sanadkii 2011, Wuxuu u saftay Republic of Ireland U19 bishii Sebtember 2014, guushii 1-0 ee ka soo horjeeday Netherlands U19. Bishii Sebtember 4, 2015, wuxuu u saftay Republic of Ireland U21 guul 4-1 ah oo ay ka gaareen Qatar U23 kulan saaxiibtinimo oo ka dhacay Gigg Lane. 25-kii Maarso 2017, Cullen wuxuu kabtan u ahaa Jamhuuriyadda Ireland U21s si uu ugu guuleysto 1 <unk> 0 guusha Kosovo U21
UEFA Under-21 waxay leedahay isreebreebka horyaalka.