Teenage prodigy Sam Konstas has announced himself on the big stage, striking a coming-of-age century for NSW against South Australia in Sydney.

Konstas went to his maiden century on day one of the Blues' Sheffield Shield season opener, hitting 152 as the hosts went to stumps on 7-297 against South Australia at Cricket Central.

One of the leading lights of Australia's U19 World Cup success last year, Konstas has long been touted as one of the country's best young talents.

And the opener showed why on Tuesday.

The 19-year-old cover-drove superbly throughout his innings, and took to spinner Ben Manenti by hitting him down the ground for three sixes.

He then brought up his century off his 163rd ball in the final over of the second session, nudging Brendan Doggett down to backward-square for a single.

Konstas's first Sheffield Shield ton came with Australia's chief selector George Bailey in attendance.

"It was an amazing achievement. Obviously, it's good to get my first one," Konstas said.

"I just have to be hungry for runs. And whatever teams I make, it's a bonus."

Konstas made his Shield debut for NSW last summer, and amid glimpses of promise he brought up a maiden half-century in the last round against Queensland.

But he looks a far more accomplished and confident batsman this summer.

He used his feet well to spin, and swept Nathan McSweeney for a big six before offering up his only chance with a missed stumping by Alex Carey.

The youngster then brought up 150 by flat-batting a Lloyd Pope full toss over the legside.

He was eventually caught at slip off the leg spinner, when adjudged to have inside-edged a ball onto Carey's legs before it was caught by McSweeney.

Meanwhile for Victoria, Marcus Harris has sent a subtle reminder to selectors about his Test capabilities, hitting a century in his first Sheffield Shield innings of the summer against Tasmania.

Harris brought up his 28th first-class century just before tea on Tuesday, and went to the break on 110 not out with Victoria 2-208 on day one after being 2-21 early.

The former Test opener's runs came as part of a big third-wicket stand with Peter Handscomb, who was unbeaten on 88 at tea.

The century was Harris's seventh at Junction Oval, with national selector Tony Dodemaide among those in attendance.

Australia's selectors face several big decisions around the opening role in the next six weeks ahead of the first Test against India in Perth.

Most crucially they must determine whether Steve Smith holds onto the role as an opener, or whether they would prefer he move back down the order to number four.

Cameron Green and Travis Head could both loom as options to move to the top in Smith's place if required, keeping the playing XI the same as last summer.

AAP