One of the 13 will be high-class flat galloper Indikator, who is making his jumping debut as a 10-year-old.
Te Aroha co-trainer Keith Opie has delayed that jumping debut as long as he dared.
"I've been looking for excuses not to run him, but Craig [Thornton] rode him at the jumping trials and said: 'There are no excuses, we should be at the races."'
Opie hopes Indikator will not be lost to flat racing - he even has ideas on a remarkable fourth Rotorua Cup victory.
"Whatever the result of this race, it's almost certain it will be his only jumping start this year. Something extraordinary would need to happen to change that.
"I'd like to spell him and see him come back next year for three or four flat races.
"If he still wants to be a racehorse and he's still fast enough, there's no reason he can't have another crack at the Rotorua Cup.
"Hopefully, he'd get a weight that is appropriate for a 10-year-old."
Indikator won the Rotorua Cup in May under a tough 59kg and in his two subsequent flat races carried a near-impossible 61kg and 60kg.
"I know the Rotorua Cup might be a dream, but he's no ordinary horse in the right conditions."
Craig Thornton will ride Indikator on Saturday.
The open hurdles includes the Sydenham and Hawkes Bay Hurdles winner Sea King, Grand National Hurdles runnerup Yamanaura, Ken Browne Memorial Hurdles winner The Strutter as well as the up-and-coming Thornton-trained Brer.
Grand National Steeplechase winner El Patron goes around in the Pakuranga Hunt Cup on his way to the Great Northern.
