 Kọ itẹsiwaju fun paragirafi yii - Ṣaaju ki o to ṣiṣẹ ni NHL, Giroux ṣe iṣẹ ọdọ rẹ pataki pẹlu awọn Gatineau Olympiques ti Quebec Major Junior Hockey League QMJHL, nibi ti o ti ṣe iranlọwọ fun ẹgbẹ lati ṣẹgun 2008 Presidents Cup ati ki o gba Guy Lafleur Trophy bi 2008 playoff MVP. Ní àgbáyé, ó gba àmì ẹyẹ góòlù pẹlú Ẹgbẹ agbábọọlù Canada ní 2008 World Junior Ice Hockey Championships : ó ṣe tán. 