The 24-year-old Santner was New Zealand's best player in Australia's four-wicket victory, that levelled the three-match series, scoring 45 not out and marshalling his side to 281-9 and then taking 3-47 with his left-arm spin.
Leg spinner Ish Sodhi has been brought into the squad as precautionary cover, should Santner not be fit enough to play at his home ground at Seddon Park.
A decision on Santner's fitness would be made just before the match, New Zealand Cricket said in a statement on Sunday.
Santner, who only made his international debut last year, is quickly impressing as an automatic selection in all formats of the game with his fluid batting and handy left-arm spin.
He has scored 35 and 45 in the two matches of the series, without being dismissed, and guided the tailenders through to the end of New Zealand innings in both matches.
Original source: Santner a doubt for NZ in final ODI