So at 3.40pm on a teasing Melbourne day, hot in the sunshine but chilly in the shade, the moment arrived for Australian Test cricketer number 441, Joseph Anthony Burns.

The young Queenslander jogged down the steps from the changing rooms onto the Melbourne Cricket Ground, leaving his security detail behind, deaf to the ovation from 70,000 in the stands. He held his bat by handle and blade, as if running a three, and hit the turf at a sprint, keying up his legs after waiting four hours for his turn.

In the middle, Burns joined Steve Smith, three months his senior in age but 80 international appearances, nearly 2000 Test runs and the Australian captaincy richer in cricket experience. Both were born in 1989, between Allan Border recapturing the Ashes and the fall of the Berlin Wall. Smith might have had more knowledge of the former, Burns of the latter; the only thing the debutant has over his captain is several years of school and university education.

The score was 4-184, the time was 10minutes into the evening session, and the Test match was poised. Burns did not have to face the next ball, Shaun Marsh having lost his wicket to the last delivery of Mohammed Shami's previous over. Smith defended Ravi Ashwin for four balls, then turned over the strike. Burns scratched his guard, strode down the wicket to tamp down four or five imaginary blemishes, and tried to remember to breathe. To his first ball from Ashwin he lunged like a swimmer off the blocks, propped awkwardly to defend, but survived. One ball! Next stop, one run!

The milestone came from the last ball of Shami's next over. Burns had ducked a bouncer, defended tightly and then timed a forward press nicely through cover point. The crowd roared and Burns, having made three, grinned as if it was a hundred. After being dismissed for one in his first Test innings, Michael Hussey said he was thrilled:

"At least I wouldn't end my career without having made a run".

Next stop – what? Burns was seeking more runs, of course, but also a perception of quality, of belonging. This perception of "Test match calibre" is impossible to define but easy to quantify. Ask Ed Cowan, to whom the perception does not, in the selection room, currently attach. Ask Shane Watson, who has lugged that perception about with him for exactly one decade. Since the first week of 2005, the selectors have been drawn to Watson as a child is drawn to an ice-cream on a hot summer's day. It might have fallen off its stick, it might be all over your hand and halfway up your arm, but hey, it's still ice-cream. On Friday, Watson played yet another of those innings that had "quality Test match batsman" written all over it except, finally, on the scoreboard. Dropped on 37, he surrendered his wicket on 52, proving nothing and everything. Again.

The perception of quality also attaches to Marsh, whose innings typified his career so far as much as Watson's had his. Marsh dug in, dragged Australia out of a mini-crisis, looked every inch a Test player, and then lapsed in the transition from act one to act two. Like Watson, and also Chris Rogers, he had gone to the brink of making some conclusive statement, some certification of authenticity, but fell just short.

Burns' opportunity now beckoned. He advanced on Ashwin, who had bowled a tight slow-medium pace all day, and lofted him to the boundary wide of mid-on. He dabbled and missed Ishant Sharma's first ball, but guided the next for a four behind point. He had made a start, arriving at 13 runs in 15 balls, quicker than any other player.

But – hare and tortoise – it was the slowest of those, the most patient and studied, who made the most runs, and about whom the perception of quality is a reality. For four years from 2009 to 2013, every time Smith had gone to the wicket there was a sense of "is he or isn't he?" The selectors thought he was, and they were proven right, but they needed to hold their nerve. He didn't always look the most assuring figure, but now Smith's fidgets have become familiar and even comforting, like Ian Chappell's box-adjustment. Quietly, while his teammates were facing their personal challenges but not quite surmounting them, Smith composed another substantial Test innings that may yet inflate in value as the match goes on.

Burns, meanwhile, having got through his first quarter-hour, looked quite at home. Then he stalled. He watched Smith play out an over, blocked out an Ashwin maiden, and watched Smith defend the first four balls of Umesh Yadav's new spell. He had played one poor shot – to his first ball from Sharma – and now he played another, to his first ball from Yadav, misjudging the bounce as he pulled. Unluckily perhaps, he under-edged and was caught. It had been a tantalising debut on a tantalising day when plenty of good cricket was waged, but, for an Australian batting line-up in transition, it was a day on which nobody really answered the big questions except the man who didn't need to.