The Highlanders began the review of their disappointing season yesterday, including players and coaches reviews, and the future of coach Glenn Moore is under the spotlight.
Moore has one year left on his contract but that may not save him after a disappointing year for the side.
The Highlanders won only three games, and ended up in 12th position, one place lower than last year.
Moore has said he is passionate about the franchise and wants to continue but ultimately it is not up to him, as the New Zealand Rugby Union will make the decision.
Assistant coaches Peter Russell and Barry Matthews are off contract this year.
Henderson and Culhane, coming off a great season with Southland last year when the side won the Ranfurly Shield and made the semifinals of the national provincial competition, would appear to be the obvious candidates to take on the job.
But Henderson said yesterday when contacted he did not want to comment on whether the duo would seek the job.
He said out of respect for the present coaching team, he did not want to say anything about what the pair's intentions were.
He said the duo would only discuss their decision on whether to seek the coaching job after the review was finished.
Moore's future is not expected to be finalised until the end of next month.
Culhane and Henderson have coached the Southland side for five years, slowly making the side competitive.
The pair not only coach together but they also work together as they run the Southland and Central Otago franchises of The Barn Company, which constructs barns right around the South.
Henderson and Culhane are committed to coaching Southland for another year, with the Ranfurly Shield on the line.
Rugby Southland chief executive Roger Clark, who has been seconded to the Highlanders for three months as project manager, will be well aware of the talents of Henderson and Culhane.
Wellington coach and former Otago loose forward Joseph could not be contacted yesterday but he looks unlikely to move south.
He is coaching the New Zealand Maori side in its centenary series this year and has just signed a new contract with Wellington, after starting coaching the side in 2008.
Joseph sought the Hurricanes job but lost out to Mark Hammett and is believed to be keen to land a Super 14 job.
But he may not be willing to travel south, with his new commitment with the Wellington team and business interests in the capital.
Canterbury coach Rob Penney may also be another candidate. He missed out on the Hurricanes job and wants to move further up the coaching ranks.
He could not be contacted yesterday.
