That admission puts Santner's spot in doubt. Patel was preferred in Dunedin, bowling 69 overs to Santner's 37 and taking four wickets to Santner's solitary scalp.
Santner said he enjoyed the rare opportunity to operate in tandem with Patel.
"He's obviously a very good spinner, has been for a while, it just worked out that he bowled a lot more overs than me and bowled well. It helps that they've got a few left handers there.
"I didn't bowl that badly in that game, just obviously didn't get many breakthroughs but I held up an end. It's the selectors' decision on what they want to go with Jeets, or an extra seamer."
New Zealand coach Mike Hesson said the decision will come down to the balance of the side.
"They bring slightly different qualities," Hesson said after the first test, noting Patel can handle a bigger bowling workload.
"They offer something different to left-handers and right-handers, and one [Santner] obviously bats better than the other."
Regardless of the spin selection, Santner believes that the hosts proved they were on par with the strong South African lineup.
"That day five could have gone either way, if we got them out early we could have chased a score on a reasonably good surface.
"To get them out in the first innings on a wicket that was relatively flat, I think we can take that into this game on more of a friendlier surface for the seamers."
Test bowling:
Mitchell Santner - 30 wickets at 39.70
Jeetan Patel - 62 wickets at 47.88
Test batting:
Mitchell Santner - 427 runs at 25.11
Jeetan Patel - 359 runs at 12.82
