The world number two is favourite to claim a second major crown on Rod Laver Arena against a player getting her first taste of such a momentous occasion and who reached the last two without meeting a seed.
"I would say emotionally I'll be very ready to fight, not going crazy," said the Belarusian, who is bidding to become the first woman since compatriot Victoria Azarenka in 2013 to mount a successful title defence at Melbourne Park.
"When you play your first final you kind of like get emotional and rushing things sometimes. When you're like third time in the finals, you're like, 'OK, it's a final, it's OK'.
"It's just another match, and you're able to separate yourself from that thing. Just focus on your game."
Sabalenka, 25, beat Elena Rybakina in Melbourne last year for her maiden Grand Slam crown.
She followed up by making the semi-finals in Paris and at Wimbledon before losing to Coco Gauff in the final of the US Open.
While 12th seed Zheng cannot compete in the experience stakes, the 21-year-old has been on a rapid rise to stardom and has shown she has the temperament and game to handle pressure situations.
Ranked just 143 heading into the 2021 season, she rose to number 28 a year later and will enter the world's top 10 for the first time next week on the back of her Australian exploits.
Zheng is the first Chinese finalist in Melbourne since Li Na won the title in 2014, and only the second after her idol to get so far at any major.
'Nice girl'
She has been taking inspiration and advice from Li in Melbourne and feels it is her destiny to win on the 10-year anniversary of her compatriot's title triumph.
"I believe in the destiny, yes, I do," she said, while admitting that how she handles being in a final is the big unknown against a player of Sabalenka's calibre.
All of her opponents en route to the final were outside the top 50.
"I know there is still another fight to go. I'm trying to control my emotion," she said.
'I mean, there is still going to be challenge on my side, because, you know, to arrive in the final, everybody needs to face the pressure in the final.
"Who can deal better and who can perform their tennis is the one who's going to win the match. That's one of my challenges. I need to deal with it."
Zheng won her first WTA title on clay at Palermo in 2023 and followed it up with a second on the Zhengzhou hard courts at the back end of last year.
She also made the last eight at the US Open - losing to Sabalenka in their only previous meeting - and won an Asian Games gold medal on home soil.
The pair are occasional practice partners and Sabalenka said she was not underestimating Zheng after watching her progress in recent years.
"She's a really nice girl and playing really great tennis once again. It's going to be great battle," she said.
"I think her forehand is really heavy, and she's moving well also, fighting for every point.
"She's played really great tennis, putting her opponents under pressure, playing aggressive tennis, and I think that's why she will be top 10."