Whakaotihia te rerenga e whai ake nei: I timata a Horan i tana whakataetae a-ao ki te USA i te wa o te tau 1999 <unk> 00, engari kaore i wikitoria i tetahi atu kapu tae noa ki te tau 2002 <unk> 03, i tae mai ki a Fiji. I ngaro ia i tana waahi ki a Reggie Corrigan i te 2003 Rugby World Cup me te 2004 me te 2005 Six Nations Championship, engari ko nga mahi kaha mo Munster i kite ia i a ia e whakahoki ana i tana waahi ki te roopu. I puritia e ia tona wahi mo te
2006, 2007, 2008 me te 2009 Six Nations Championship, te tiimata i nga whakataetae katoa o te pakanga toa a Grand Slam o Ireland. Ko ia hoki tetahi waahanga nui o te kapa kapa Rugby World Cup 2007 a Eddie O'Sullivan. I ngaro ia i nga Whakamatau o Noema 2009 i muri i tana pokanga ngakau, a ka ngaro tana waahi ki a Cian Healy, i mau ki te tuunga o te upoko o te upoko i te 2010 Six Nations Championship. I takaro a Horan ki te Barbarians F.C. me te Maori o Niu Tireni i nga Whakamatau o te Raumati o Ireland i te tau 2010, engari i whakakorea ia i nga Whakamatau o Noema 2010 me te ringa pakaru. I ngaro ia i te 2011 Six Nations Championship, engari i tohua ia ki te roopu whakangungu a Ireland mo te 2011 Rugby World Cup warm-ups i Akuhata 2011. I takaro ia ki a Scotland, engari i ngaro ia i te whiringa i roto i te roopu whakamutunga mo te Ipu o te Ao.