"We were slightly fortunate to get the win last weekend and our discipline very nearly let us down.
"Players have to play to the rules and control physicality, especially with the loss of two key aggressors around the scrum."
Greerton Marist have had a difficult start to round two of the Premier competition - losing three of their four games, including last weekend's 46-7 loss to second-placed Tauranga Sports.
And Rotoiti can take confidence into the crucial fixture having beat their next opponents 30-28 in round one of the competition - a nail-biting win once again sealed late by Henry.
"We know we can beat them," said Emery.
"But none of us want to see a repeat performance from last time."
Tomorrow's games:
Baywide Premier 1
Kick-off 2.45pm/Development kick-off 1pm
Rotoiti v Greerton Marist, Emery Park
Whakatane Marist v Te Puke, Rugby Park
Tauranga Sports v Rangataua, Tauranga Domain
Te Puna v Mount Maunganui, Maramatanga Park
Baywide Premier 2
Kick-off 2.45pm/Development kick-off 1pm
Opotiki v Whakarewarewa, Princess Street Reserve
Waikite v Arataki, Bellvue Road
Ngongotaha v Marist St Michael's, Ngongotaha Domain
Paroa v Poroporo v Poroporo, Lawson Park
Baywide Division One
Kick-off 2.45pm
Judea v Kahukura Maharaia Winiata Memorial Park
Ruatoki v Papamoa, Tuhoe Park
Rangiuru v Katikati, Centennial Park
Edgecumbe v Te Teko, Edgecumbe Domain