Expecting Hammond to take a bench spot, Caskey had already granted permission for 26-year-old Josh Lane to keep hunting trip plans he made before the start of the representative season.
The team is therefore hoping Fijian test veteran Sekonaia Kalou's ankle has come right sooner than intended, with Cade Robinson on stand-by.
"It just continues the year we've been having, really," said Caskey.
One virtue amongst the necessity is the WRFU's commitment to the Whanganui Maori rugby programme - scheduling three games in the past few weeks - has now proved vital with both Robinson and returning reserve prop Gabriel Hakaraia being match fit, as is last weekend's Wanganui debutant Ethan Robinson, who was elevated into his fifth different representative team in two months.
"That has been the good thing - [Hakaraia]'s been able to get plenty of game time," said Caskey.
"That's part of the idea, getting some younger guys involved to set them up for next year and beyond."
As well as pumping up the youngsters for their first sudden-death playoff, Caskey and his coaches have been instilling in the squad the belief that, despite barely scraping into the Top 4, they can still hang with the top-of-the-table Cantabrians, who are on a seven game winning streak including victory in the side's last encounter in Timaru 21-17.
"They're excited. Hung around on Saturday night until just after the Mid Canterbury result came through, but West Coast was still going," Caskey recalled of that crazy three hour period.
"We had a function in Waverley, but the boys were ringing around asking what was happening.
"Confusing period of time. You never have complete trust on being told you're in.
"Once you're there, you're there, it doesn't matter how you got there."
Therefore, the leadership team of centenarian Cole Baldwin and his deputy Roman Tutauha, who like their team have never lost a Meads Cup semifinal, will have to get the most out of the limited resources available.
"These two guys making the decisions have plenty of experience. Good heads, don't get too excited," said Caskey.
"The one thing we probably have going in our advantage is a lot of people who have played a hell of a lot of Meads Cup semifinals and finals.
"There's no bonus points for scoring four tries. I'd be happy to kick five penalties and win 15-12."
Players aren't the only ones getting tinkering in the trainer's room, as Wanganui will not be able to take another direct flight as they did in September because sponsors Air Chatham's are doing maintenance of the aircraft which took them, meaning the squad will fly the traditional route of Palmerston North to Christchurch followed by an over two hour bus ride to Timaru.
Upon arrival they will face a strong home side probably becoming quite indignant about being denied Meads Cup glory over these past three seasons - with Wanganui being one of the main culprits for why not.
"They'll have the pressure [of] not getting through it," said Caskey.
Experienced coach Barry Matthews has players coming in through his revolving door of injury, rather than going out.
Hawke's Bay loan fullback Liam Edwards, centre Shayne Anderson and wing Setefano Sauqaqa could all be back in the starting lineup.
While first-five Miles Medlicott may not be over his broken thumb, Jared Trevathan and prolific points-scoring halfback Willie Wright will have that covered.
There are also a lot of wraps on outside backs Vatiliai Tora and Kalavini Leatigago - each with seven tries this year including Leatigago's brilliant solo effort against Wanganui in September.
The South Canterbury union has called their banners, imploring all home supporters to be there to lift their side to victory and deny Wanganui a shot at a historic Meads Cup three-peat.
Kick-off is at 2.30pm.
The Wanganui team is:
1. Kamipeli Latu; 2. Cole Baldwin (c); 3. Hamish Mellow; 4. Sam Madams; 5. Campbell Hart; 6. Tremaine Gilbert; 7. Jamie Hughes; 8. Bryn Hudson; 9. Lindsay Horrocks; 10. Cody Hemi; 11. Cameron Crowley; 12. Dane Whale; 13. Kaveni Dabenaise; 14. Simon Dibben; 15. Nick Harding.
Reserves - Forwards: 16. Roman Tutauha (vc); 17. Gabriel Hakaraia; 18. Sekonaia Kalou/Cade Robinson; 19. Angus Middleton. Backs: 20. Tom Stewart; 21. Ethan Robinson; 22. Samu Kubunavanua.