Otago need to be more urgent around the ruck, coach David Reedy says.
The Whalers will travel to Rotorua to play Bay of Plenty tomorrow.
The two teams last meet in 2017 and the Bay sneaked a close win.
But the Bay pushed a talented Auckland Vulcans side last weekend and shape as tough opponents.
"The North Island teams bring that physicality around the ruck and we’re not used to that kind of intensity," Reedy said.
Lifting the effort in that area has been the focus this week.
"We just need to be a bit more prepared in the contact area. We’re trying to be a little bit more urgent in the tackle situation when we’ve got the ball.
"We need to try to play the ball a bit faster. We tend to lie there a little bit longer, which gives the defence more time."
The Whalers have made a bunch of changes to the side which was beaten 35-18 by Counties-Manukau in Dunedin on Sunday.
Prop Mika Mafi was punched in the face in that game and left the field with a suspect fractured eye socket. He is still recovering.
Benji Latu, who is returning from injury, will take the spot vacated by Mafi.
Winger Mone Samate is unavailable this weekend. But Opeti Tuimana returns from injury and will play on the wing.
Midfielder Aleki Morris-Lome is out injured and his place goes to Siua Fonua.
And Troy Anstiss moves back into the second row with the return of hooker Eli Ellison.
Otago was outclassed by Counties-Manukau. The visitors played the majority of the match down a man after Tahi Baggaley was red-carded following the punch he landed on Mafi.
But despite that, the visitors were able to pressure the Whalers and won comfortably.
Bay of Plenty, however, should be more on the Whalers’ level.
The Bay lost their opening game to Counties 40-0 and followed that up with a 42-24 loss to Auckland.
The Whalers beat Waikato 48-24 in their opening game.
NZRL premiership
Rotorua, noon tomorrow
Otago: Max Brown, Opeti Tuimana, Tama Apineru, Siua Fonua, Mavae Mahuika, Keenan Masina, Jordan McEntee, Cameron Brown, Eli Ellison, Benji Latu, Troy Anstiss, Misinale Fifita, Hagan Free, Oscar Anderson, Tofatu Solia, Sefo Muasika, Jake Day, Orlando Tuhenga-Vaitupu.
Bay of Plenty: Connor Hohepa, Twoboys Junior Taia, Cameron Walters, James Leavai, Ethan Tetevano, Vincent Morunga, Caleb Piua, Jamin Pinkerton, Troy Brown, Daniel Holmes, Kaisa Matautia, Dylan Shortland, Blake Ayshford, Mohi Lyttle, Rewiti Brown, Dylan Clark, Caleb Lepaio Gamlen, Caelys Paul Putoko.
