At the start of the following season, both O'Donohoe and Murphy were absent due to injury, meaning Connacht academy scrum-half Kieran Marmion stepped into the role. Marmion played impressively in the absence of the two senior players and went on to start every competitive game the province played that season. O'Donohoe made 12 appearances in the 2012–13 Pro12, all of them coming from the bench, along with four substitute appearances in the 2012–13 Heineken Cup.