With key forwards Max King and Tim Membrey among the sidelined players, Caminiti will probably feature against Fremantle on Sunday at Marvel Stadium.
After missing out in the national draft, 19-year-old Caminiti was training with Carlton's VFL side when Blues player Jack Silvagni mentioned him to his dad, Saints recruiter Steve Silvagni.
The Saints invited Caminiti to train with them last month and quickly signed him after he made an immediate impression.
Phillipou was recruited with pick No.10 in the national draft and has enjoyed an impressive pre-season.
"Caminiti has come from the clouds, hasn't he?," coach Ross Lyon said.
"It's likely we'll have those two, Phillipou and Caminiti, as debutants."
Lyon added he had "no rabbits in the hat" to deal with the absence of King (shoulder) and Membrey (knee).
Mitch Owens will play in attack as a tall marking option.
The Saints have 14 players out of action ahead of round one, but Lyon said he does not detect a problem with their training regime.
"There's no soft-tissue crisis - as a coach, you think 'soft tissues'," he said.
"Clearly the ones we'd love to have are our key power forwards.
"Other than that ... the 23 we pick will all have had full summers and be fit.
"I'm not overly stressed."Â
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