Zampa could have played Wednesday's decider at Ninja Stadium for the Blues but didn't want to take the field at the expense of fellow leg-spinner Tanveer Sangha.
The 24-year-old Sangha is the leading wicket taker in this season's domestic one-day competition, with 18 across seven matches at an average of 18.05.
Zampa has played a solitary one-day cup game for NSW this season, but became available following Australia's early Twenty20 World Cup exit.
Patterson said there was a chance Sangha and Zampa could have both played if it was a day final and not a day-night fixture.
"It was really selfless," Patterson said of Zampa's call.
"There's always a balance there between going chips in … and rewarding someone like Tanveer who is leading the competition and doing more than his job.
"If it was a day game, it probably looks different and you're probably going in with two leg-spinners.
"It was a bit of a team balance thing."
NSW will have World Cup squad members Sean Abbott and Ben Dwarshuis back on deck, while Nathan Ellis and Matt Kuhnemann return for Tasmania.
Tasmania secured hosting rights for the final after winning their first five matches, but dropped their final two games including to NSW in the last of the regular season.
Needing a bonus-point win to make the final, NSW chased down 274 in just 31 overs off the back of Patterson's unbeaten 125 from 89 balls.
Patterson, captaining NSW in the absence of Jack Edwards, tops the season run tally with 513 at an average of 102.60.
"I've found a bit of a rhythm to my one-day batting I haven't had in the past and turned some of those starts into hundreds," he said.
Tasmania haven't lifted the one-day trophy since 2009-10 courtesy of a side featuring George Bailey, Tim Paine and James Faulkner.
"There's a nice bit of motivation to create some of our own history," captain Jordan Silk said.
"It's something I'm really keen to bring home. There were some great names in that line-up."
Forecast rain could play a part in the result. If the game is washed out, Tasmania claim the title as the team higher on the ladder.
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