 In October 2012, Due to the absence of Ricki Herbert due to international duties, Greenacre was appointed as the caretaker manager of the Wellington Phoenix for their Round 2 clash with Melbourne Heart.Despite missing 7 first team players due to international duties, and despite playing an away clash, the Phoenix managed to obtain a 1–1 draw with the Heart, courtesy of a Paul Ifill penalty.On 26 February 2013, Greenacre was appointed interim manager of Wellington Phoenix until the end of the season after Ricki Herbert resigned.