Carvell (48), a director of Williams Signs, said he wanted to keep the assistant coaching job, but ruled out applying for the head coaching position.
He was brought into the job halfway through last season, replacing Glenn Moore, who took on the Highlanders head coaching job.
Carvell said he had enjoyed his time as assistant and felt there was still unfinished business.
The Otago Rugby Football Union announced on Monday it would advertise the position of both coach and assistant coach for Otago in 2009.
Head coach Steve Martin's three-year contract had finished at the end of the season, in which the side placed 10th in the Air New Zealand Cup.
Martin indicated he would seek the position again.
Carvell said yesterday he would not stand against Martin for the head coaching position, but wanted to continue as assistant. There were many good young players coming through, he said.
Carvell played as a loose forward for Ravensbourne.
He has coached Harbour premiers, and various Otago sides, including Otago under-19 to a win in the transtasman trophy competition, Otago Colts, and Otago B to the national title in 2006.
