Agar had a meteoric start in his Test career, scoring 98 on debut in the Ashes opener against England at Trent Bridge in July.
But he failed to replicate those heroics with the ball, snaring just two wickets at an average of 124 over two Tests before being dropped for the rest of the series, which Australia lost 3-0.
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Agar idolised Warne growing up, and the teenager was able to pick the brain of his hero before the third Test in Manchester.
The youngster knows he has a few technical issues to work on, but it's the tactical nous he gleaned off Warne that could have immediate benefits.
"He just talked a lot about game sense, tactical moves and everything that comes with spin bowling," Agar said.
"I was able to learn a lot from him.
"With Shane Warne, if he didn't get you out one ball, he'd make you feel like he was going to get you out the next.
"That was one of his greatest strengths.
"Obviously he had a lot of skill. But he accompanied that with his great tactical mind and theatrical side."
Agar was forced to return home early from the Ashes tour due to a virus.
Although doctors weren't able to pinpoint exactly what he had contracted, subsequent blood tests cleared him of anything serious.
He is now looking forward to the Perth Scorchers' Twenty20 Champions League campaign in India, which starts on September 17.
The Victorian-born left-hander has done well to stay grounded despite the hype over his potential.
"I guess my life has changed a little in the way that you might walk down the street and a couple of people might say 'well done' or 'congratulations'," Agar said.
"But other than that, I'm still exactly the same person."
The start of the Sheffield Shield season is a pivotal time for Agar if he is to win back his Test spot in time for the forthcoming Ashes.
Western Australia coach Justin Langer says Agar learned valuable lessons from his axing in England.
"It's a tough time in the sense he was left out, but he'll be better for this experience," Langer said.
"He's a smart guy, so he'll work things out."