Marcus Harris was the highest scorer in Sheffield Shield cricket over the last two summers, but a conversation with Australian Olympic legend Cathy Freeman during the winter helped him become the newest member of Australia's Test squad.

Harris' manager, James Murch, is Freeman's husband, and Harris jumped at the opportunity to speak to her. Freeman provided him a platform to expedite his own development.

The surreal nature of sitting in the kitchen of Australia's most famous Olympic Gold medallist, essentially answering his own questions being the talkative 26-year-old that he is, while Freeman listened and occasionally chimed in with her own story of handling the pressures of expectation and cutting out the white noise to focus purely on her performance, left an indelible mark on Harris.

Four Shield matches and 437 runs later, Harris is in Australia's 14-man squad to play the first Test against India in Adelaide.

"I've probably just got older and I've matured a bit more," Harris said. "Just being able to back up games after games and just to be consistent has probably been my main focus in the last couple of years and it's probably gone to show with my results."

He has matured off the field too. His girlfriend has moved in with him and they have a puppy, a French bulldog named Archie.

"I got a call from Trevor Hohns last night, I'd just got home from puppy pre-school with my dog," Harris said. "Two very different situations to be in. All I remember was he said 'you're in the Test squad' and I can't really remember what else he said, I went into a bit of shock. He just said well done and well deserved."

The process took years for Harris, as it does for most cricketers. His first-class career is a tale of two halves.

He started as a precocious teenager, when as an 18-year old he scored 157 in first-class cricket. But in 41 Shield matches across six seasons with Western Australia he managed just 2047 runs at 28.43.

A sea change was needed at the end of 2015-16 and he moved to Victoria. Harris has since scored 1951 runs, more than any other Shield player in that time, at 47.58 with five hundreds in 44 innings.

Much has been made of Harris' relationship with Australia coach Justin Langer after his exit from the Warriors nest, and Langer wanted to set the record straight.

"Let me squash this straightaway, Marcus Harris is like my little brother," Langer said. "I've known him at Scarborough Cricket Club since he was about 10 years old. Did I say mediocre with flashes of brilliance? Yeah, I did, because that's what he was. That's the truth.

"What he's done to his great credit is, he's become a really consistent opening batsman with flashes of brilliance. That's what really good players do and that's why he's been selected to play for Australia.

"I keep reading headlines there's a big thing about Justin Langer and Marcus Harris because he said he's mediocre. He's my little brother. I love him. I love him. He makes me laugh every time I see him.

"When I read those things it's like a dagger to my heart because I know it's actually not what happened. He came to Victoria for a lot of reasons, not just cricket reasons. I'm really happy to see him get selected."

Langer texted Harris after his 250 not out against New South Wales, and sent another last night saying, "welcome to the brotherhood you little b******".

The reality is Langer didn't want Harris to leave. The paired mulled over the decision in a coffee shop in East Perth for 90 minutes in the winter of 2016 before Langer finally agreed that Harris needed to move for his own development.

"We had a really good meeting when I left WA and I know we ended on good terms," Harris said. "I understood if you put a lot of time into someone and they leave the state you'd be upset. That was fine by me and it's all good, no worries there."

Langer had been desperate to see Harris succeed. He picked him for 2013-14 Shield final when Harris' eight Shield scores for the summer had yielded just 137 runs, convinced the young man's work ethic and hunger would pay dividends. It didn't in that final, but it did 12 months later, when he scored 81 and 158 not out in the 2014-15 final against Victoria.

But more maturity was required, and with a big hug and an honest clip from the coach, Harris boldly moved east where he reconnected with Langer's predecessor, Victoria's batting coach Lachie Stevens.

The pair have gelled. Stevens' pragmatic approach to batting fits in with Harris' personality. Together, they have unlocked what Langer was searching for.

"I know I spoke to Lachie Stevens several times throughout the pre-season, we were just talking about trying to turn 700-800 run seasons into 1000 and that's just about batting time," Harris said. "I knew I could make the runs, but batting time's probably a bigger thing for me because I know the runs will come. It was definitely a focus of mine throughout the pre-season."

Harris' strike-rate has dropped from 65 last season to 55 this year, and his average has gone from 41 to 87, albeit inflated by a score of 250 not out.

His task now is to transfer his new-found maturity to Test cricket, where the white noise becomes deafening, as his phone rings off the hook with family and friends wanting tickets to the game, and the spotlight intensifies with more media attention on him than ever before.

Harris knows a Test debut is no Sydney Olympic 400m final, but Freeman's words could well hold him in good stead.

Alex Malcolm is a freelance writer based in Melbourne