Kubler is back in the main draw after scrapping through qualifying this week.
"It feels good. I wasn't sure if I would be back," a frank Kubler said.
The 32-year-old's reward is a challenging match-up with Tiafoe, a two-time US Open semi-finalist, a 2019 Australian Open quarter-finalist and a man who has beaten him in straight sets in three previous encounters.
But with nothing to lose against the 29th seed and a raucous home crowd at John Cain Arena at his back, Kubler is ready to turn the tables.
"I know I've lost to him every time so far, but we'll see," the former world No.1 junior said.
"We'll see. I'm a bit older now. I got a bit more experience. I'm probably enjoying tennis bit more now, just because I probably think the end is getting a bit closer.
"And then with the way the Aussie fans are, anything can happen here for me."
Kubler's fiancee, fellow Aussie pro Maddison Inglis, insisted "Jason can beat anyone" after the newly engaged couple both reached the main draw.
"Anytime you play a big gun, you know they're obviously high in the rankings for a reason. You know they don't lose a hell of a lot," Kubler said.
"So I guess anytime you have to go up against one of them, it's kind of 'alright, let's give it all I got, and let's see if it's good enough on the day.'"
The veteran, who missed last year's tournament and lost in the opening round in 2024, has already identified what he needs to get right against 27-year-old Tiafoe.
"Everyone knows that probably the trouble I've had against him is it just feels like he's just a little bit better in probably most of the areas than me," Kubler said.
"He's got a big serve, very solid backhand, great forehand.
"So I think I'm just going to come up with some good tactics, play my game, and then if I can get an opportunity to break or to win a set, just really capitalise on that.
"Tennis nowadays is just about those one or two points here and there. If you can play well in those big moments, then you can do well against almost anyone."
Kubler is one of four Australians in action on the opening day.
Adam Walton has the daunting distinction of facing world No.1 Carlos Alcaraz in the feature night match on Rod Laver Arena.
On KIA Arena during the day, Talia Gibson will play Russia's Anna Blinkova before Tristan Schoolkate takes on fiery French 32nd seed Corentin Moutet.
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