McBreen's debut for the Glory came when he entered a 6–2 away loss to Melbourne Victory as a 38th-minute substitute for Chris Coyne on 16 January 2010. He started and scored in the next match three days later, a 3–2 away win over Adelaide United, with the winning goal in the 77th minute. This marked the start of a run of five goals from four matches, helping the Glory finish fifth in the 2009–10 A-League table and thus qualify for the finals series. McBreen played in their 4–2 penalty shoot-out defeat to Wellington Phoenix in the fourth v fifth semi-final on 21 February, which followed a 1–1 draw after extra time. He had scored five goals in seven appearances for the Glory, and with eight goals altogether he was the 2009–10 A-League's eighth highest scorer. His good form was rewarded with his first call-up for the Australia national team.