Whittaker, 29, has returned to Sydney following his unanimous-decision victory over Darren Till as part of the run of fights at the UFC's Fight Island.
After losing the first round -- during which he was floored by a thumping left elbow from Till -- on all three judges' scorecards, Whittaker recovered to take control of the fight and claim victory with a dominant showing in Rounds 2 through 5.
"I expected a hard fight. He's a good fighter. He's very good striker. He's fought five-rounders. He's fought for the title," Whittaker told ESPN. "So feeling him out in the fight, it was like a chess match. It was honestly one of the most intensely taxing fights of my career thus far.
"He had a very good game plan of trying to counter me, to expose me when I blitzed in. And it worked because in Round 1, I jumped in there, and I got caught on the blitz-in, and I just had to pull back and understand that this was his game plan. And for me to take advantage of that, I had to just pick him apart from the outside, chip away at his legs and go for takedowns when they presented themselves."
Whittaker was able to recover quickly when he was floored, getting his legs up in defense to prevent Till from continuing his attack. He was then able to reset and change plans in consultation with his corner at the end of Round 1.
"It was just a well-placed, well-timed shot. If it was a terrible shot, I wouldn't have got back up," Whittaker said.
"I was speaking to my corner, and hats off to my corner because they were receptive. They did an excellent job of working the corner and keeping me together.
"I told them, 'He's waiting for me. He's waiting for me to counter,' and they were saying, 'You've got to fake him out, a lot of fakes, look for the takedown if it's there and just keep chipping away,' and that's what I did."
Although Whittaker was unable to nail the takedown attempts with any regularity, he was able to clip Till on the way out with a series of "cheeky shots."
The question now is whether Whittaker (21-5) will get an immediate title shot against the winner of Adesanya-Costa, which is scheduled for Sept. 19, or will have to go through Jared Cannonier, as seems to be the preference of UFC President Dana White.
"You got Cannonier in there. Do you do Cannonier vs. Whittaker? I mean, that's a really good fight to find out who fights the winner of Adesanya vs. Costa," White told ESPN earlier this week.
For his part, Whittaker says he's ready to contest the middleweight strap before the end of the year.
"I would love that title shot. I will never turn away from a title shot," he told ESPN. "I'd love to run it back with Issy. I guess we'll wait and see.
"Right now, I'm in isolation, and my first priority is just to go and see my family and then get back in the gym and start plugging away and then see where it leads me. But I'd jump for it, mate."
After seeing off Till in Abu Dhabi, Whittaker spoke of how "terrifying" the fight was, given that it was his first after last year's defeat to Adesanya at UFC 243.
Asked to elaborate, Whittaker said it wasn't that he doubted his ability or preparation, but the prospect of being a former champion who slipped to successive defeats really played on his mind.
That is backed up by a middleweight statistic that has seen former champions slip to a collective 3-12 record after losing the belt, per ESPN Stats & Info.
"The same nerves occur for any fight, but I guess the big thing was that I was putting a lot of pressure on myself because I'd just come off a loss and I didn't want to lose again," Whittaker said. "The next fight after a loss is so hard for that reason because no one wants to lose twice in a row, especially after losing the belt.
"I didn't want to be that guy. I didn't want to be that champ that lost his belt and then went on a losing streak. I didn't want to be that guy. I'm young enough to have multiple runs ahead of me still, and I'm one of the best in the world. I believe that, and a lot of people believe that.
"So all these expectations and pressures, whether they were real or not, they're there."
Whittaker will complete 14 days of hotel quarantine in Sydney as part of the Australian government's border process amid the coronavirus pandemic.
"I was made for isolation, to be honest. You could leave me here," he said with a laugh. "Honestly, it has been outstanding ... If I had my family here, I wouldn't leave. It has been outstanding."