According to the Daily Mail, Anna passed away on the weekend from complications from surgery.
The devastated former AFL star took to Instagram to share a heartfelt tribute to his wife: "Goodbyes are not forever, are not the end. It simply means I'll miss you until we meet again. Rest easy my darling #xxx3boys."
The couple started dating in 2002, however, had known each other since childhood, having grown up together in Tasmania.
Brad and Anna married on December 28 2013, the year after Green retired from AFL.