The 37-year-old has been competing in off-road runs for 20 years and predicts the Kaimai event will be different to any others he has done in New Zealand.
"I think this one will be totally different to the Tongariro run as it is all under bush and tree cover," said Morrissey. "There will be plenty of stairs to run up, some rock hopping, and along the top between the falls and the high point, the track is very rooty with dense bush, so you have to concentrate the whole time. It is quite a cool track.
"The biggest challenge is staying focused for the whole race as there is not much of a chance to relax and no easy running where you don't have to watch your footing."
Morrissey would love to be the first winner of what is expected to become a landmark event on the Bay of Plenty sporting calendar.
"I don't go into races thinking I am going to lose and always have aspirations to win. There will be tough competition from the other guys, but I am hopeful," he said.
Race director Jason Cameron says the Kaimai course might be different to the original course but the races have plenty in common.
"The aspects that make the original Tongariro event course so great are all there with this one - the toughness, the technical terrain, the waterfalls and river crossings, the vertical climbing metres and the remote rugged setting," he said.
"The experience will, however, be different and we wouldn't be surprised to hear plenty of 'that was awesome but very different to the original' comments at the finish line."