Added preparation time away together as a group will help, as Wanganui must do without their two Ruapehu enforcers tomorrow.
After impressing in 50 minutes last weekend, the sad story of Campbell Hart's groin strain continues as the 25-year-old had another flare-up and could miss another month of rugby.
Fraser Hammond's rib injuries need at least another week and Hamlin knows the veteran is a big miss against the Cantabrians.
"They look to be a fairly big pack and got a big No8 and No6. Their front rowers look to carry well."
After being rested with injury last weekend, lock Sokonaia Kalou comes back into the starting XV with Taione Ratu staying with his bench spot.
With no Hammond, Tremaine Gilbert keeps the blindside flanker spot, while Jamie Hughes returns to open side for Angus Middleton.
The fingers were being crossed for prop Hamish Mellow to pass his fitness test, because with Gabriel Hakaraia on standby to start, there is not a lot of other front rowers left in behind them.
In addition to having to out-work a bigger pack, Wanganui must contend with South Canterbury's strong midfield, and has made changes with Kaveni Dabenaise's return to partner Timoci Seruwalu midfield, while Jona Sawailau moves back to fullback to replace teenager Cody Hemi.
There is still no place for Samu Kubunavanua, who Hamlin hopes will play the RDO Shield final for Wanganui Toyota Development, along with Hemi and Nick Harding returning from injury.
"If we get some ball, I think Jona's going to be dangerous with a bit of space. On a dry field," said Hamlin.
"I've spoke to the backs about trying to get more out of people, more communication around things.
"Don't want to seem like we're waiting on one or two people to play.
"It's just little skill execution things we're not doing as well as we like.
"The big thing is not to beat ourselves, [South Canterbury] are a good enough group to do that."
And a big part of that will be sticking to game plan and not simply trying to sweep through on every play.
"I think we look across all levels of rugby, it's the same. They've got to temper it."
Hamlin will look to first-five Craig Clare to set the tone, while halfback Lindsay Horrocks returns to the starting XV and has a point to prove after an ineffectual second half against Poverty Bay, although the 27-year-old does have a history of strong performances against South Canterbury.
Meads Cup semifinalists last year and finalists in 2015, South Canterbury have surpassed neighbours North Otago as Wanganui's toughest southern rivals in recent years.
They had a tough start with a 27-24 loss to Buller in Westport, despite scoring four tries to three, then came right with a 42-36 win over King Country in Timaru and a 31-16 victory in Ashburton against Wanganui's next opponent Mid Canterbury.
Weather reports suggest tomorrow will be overcast but fine in Timaru. Kickoff is 2.30pm.
The likely Wanganui team is
1. Hamish Mellow; 2. Roman Tutauha (c); 3. Viki Tofa; 4. Sam Madams; 5. Sokonaia Kalou; 6. Tremaine Gilbert; 7. Jamie Hughes; 8. Bryn Hudson; 9. Lindsay Horrocks; 10. Craig Clare; 11. Bruno Tuivai; 12. Timoci Seruwalu; 13. Kaveni Dabenaise; 14. Simon Dibben; 15. Jona Sawailau.
Reserves - Forwards: 16. Cole Baldwin; 17. Gabriel Hakaraia; 18. Taione Ratu; 19. Angus Middleton. Backs: 20. Tom Stewart; 21. Dane Whale; 22. Cameron Crowley.
