Former Test batsman Nic Maddinson has put his dominant century in his maiden JLT Sheffield Shield outing for new state Victoria down to the uncertainty about his spot in the side.

Months after being overlooked for a state contract with NSW, Maddinson made the perfect start to his Victorian first-class career by posting a sublime century – his ninth overall – on day one of Victoria's clash against Western Australia at the MCG.

The "exhausted" 26-year-old saw off two new balls on a reinvigorated MCG surface and batted all day to finish unbeaten on 159 from 282 deliveries, catching the eye with a series of exquisite front-foot drives.

Warriors coach and ex-Australia batter Adam Voges said it's the most patient innings he'd seen from the prodigiously talented left-hander.

Maddinson has stated his desire to return to Test level after his all-too-brief stint with Australia two summers ago and says having to win his spot in Victoria through hard work and weight of runs, rather than being daunting, has spurred him on.

"The biggest thing is I've had to come somewhere new and put runs on the board to earn selection," he told reporters after play with Victoria 3-311 at stumps.

"In a way I think I haven’t had to do that a hell of a lot.

"I started quite young in New South Wales and was always doing enough to stay in the team without having to be a match-winner or scoring a lot of hundreds.

"The thing in Australian cricket at the moment, everyone wants hundreds so that's my focus.

"There's a little more responsibility (in Victoria) put on the player and they trust that you're doing the right thing and getting the most out of yourself. It's a fairly relaxed environment."

The ton put him in the rare club of having scored centuries on first-class debut for two states, having struck 113 in his maiden outing for the Blues as a teenager more than eight years ago.

He's also the third straight Victorian debutant opener to reach triple figures after Travis Dean - taking the reins as captain for the first time in this match - and Marcus Harris also posted hundreds in their first games for the state.

It was an innings made all the more impressive given he would not have been playing had the Vics not lost three of their best batters to the Test side.

And Maddinson admits he still has no certainty over his place in the team

"I knew coming down that it was going to be tough work to get into Shield cricket," he explained.

"With the three guys getting selected, it opened a hole this week and I was scoring runs at the right time – in cricket timing is usually everything thing in terms of selection.

"It doesn’t mean I'm going to be here long term after Christmas - we might get those guys back and they might slot in and push me out of the team.

"But it's a nice start."

Maddinson moved to Melbourne over the winter in the bizarre situation being considered among Australia's best T20 batsmen but not being deemed worthy of a state deal.

While he held T20 contracts with KFC Big Bash club Melbourne Stars and English county side Surrey, Maddinson still had eyes only for his Baggy Green.

Last week he barged the selection door down, posting 150 in the Toyota Futures League to back up some strong form at Premier Cricket level with St Kilda, where he's captained by another former Test player in Michael Beer.

"I was really enjoying playing cricket for St Kilda and getting yelled at by Michael Beer every now and then," he said to laughter.

One of Maddinson's few errors on Friday somehow resulted in the wicket of teammate Glenn Maxwell rather than his own.

On 92, he flashed a return catch to bowler Matthew Kelly, who bungled the reflex catch but accidentally parried the ball onto the bowler's end stumps with Maxwell short of his ground.

"We were just laughing about it … He's fine in the rooms," Maddinson said of Maxwell.

"I keep telling everyone that backing up is overrated.

"He was playing (well). He did a lot of hard yards in terms of getting through some tough spells and some pretty disciplined bowling.

"It seems to happen fairly regularly in cricket. I was just happy he dropped it."