Rob Penney played 101 games for Canterbury, then ten years later, took on an Assistant Coach role in the provincial side in 2003, winning the NPC trophy and the Ranfurly Shield in 2004. In 2005, Rob was an Assistant Coach for the Crusaders Super team which won their fifth Grand Final, beating the Waratahs 35-25 at Jade Stadium. 

Rob then took over the Head Coach position of the Canterbury provincial side in 2006, going on to win four provincial championship titles between 2008 and 2011. In 2012, Rob was also the Head Coach of the NZ U20 side, making it to the finals of the World Rugby U20 Championship against South Africa in Cape Town. After the U20s, he headed to Munster in 2012, reaching the semi finals for two seasons of the Heineken Cup, narrowly losing both games to French teams in France. He also led Munster to the Pro 12 semi final. His hard work was recognised as he was awarded the 2013–14 Pro 12 Coach of the Season.

Rob then spent time with Shining Arcs in Japan and assisting the national Japanese U20s team before reconnecting with the Waratahs during the tumultuous covid time. In 2024, Rob returned home to his beloved Christchurch taking on the Head Coach role of the Crusaders.