With Labuschagne as third seamer, there's a very un-Australian Australia at the SCG

When Marnus Labuschagne was marking out his medium-pace run-up, although maybe not entirely seriously, alongside Pat Cummins and Josh Hazlewood before play on the opening day at the SCG, you knew this was not going to be a type of balance often seen for an Australia Test team at home.

It had been one of the more fascinating lead-ins to a Test in this country, through a combination of conditions and the injuries Australia had suffered, most significantly the one to Cameron Green and the challenge of effectively replacing two cricketers.

One of the traditions of the New Year Test is to debate the use of two spinners. This time, both teams went that way. What was something of a surprise from Australia was that Ashton Agar formed a four-man attack with Cummins and Hazlewood as the only quicks.

Leaving aside their brittle batting for a moment, it actually felt like South Africa had the better balance of attack with Simon Harmer included alongside Keshav Maharaj and three specialist quicks. It was the first time since the Super Series Test in 2005 that both teams had gone with two frontline spinners.

"I don't think I've played on a wicket that's turned from the middle as much as it did today," Labuschagne said about a dry pitch already taking turn.

For Australia, Hazlewood was returning from a side strain, and in two of the four Tests this season, Australia have suffered an injury to their pace attack which removed a bowler: Cummins in Perth and Green in Melbourne [Mitchell Starc battled pain to continue]. It felt like something of a risk to put all the pace bowling in the hands of two.

But Australia wanted some batting security with a specialist No. 6 so Matt Renshaw got the nod - and not long after the toss tested positive for Covid-19. Whether he actually completes his Test return remains to be seen. Spare a thought for Marcus Harris, who has travelled all summer as the reserve batter, and even now is unlikely to be the one called in if a sub is needed.

However, it was the make-up of the attack that was most interesting. While 2016-17 was the last time Australia had played two frontline spinners in a home Test - when Nathan Lyon was partnered by Steve O'Keefe against Pakistan at the SCG - it is very unusual for there not to be what classes as a third seam option, with all due to respect to Labuschagne's bustling medium-pace.

If you look back over recent generations of the Australian team, there has been someone capable of a third-seamer role, even if their primary job was batting.

For example, when Shane Warne was partnered by Tim May against England in 1994-95, Mark Waugh was there to provide support to Craig McDermott and Damien Fleming.

Jumping forward a few years, the 1998-99 Test against England included Colin Miller, who opened bowling seam-up before switching to offspin. The ultimate funky selection. Glenn McGrath was the frontline quick that day, but if needed, Steve Waugh was available; by then, Mark Waugh's back had forced him to turn to offspin.

After Steve Waugh had left the scene, Warne and Stuart MacGill were paired at the SCG but by then Shane Watson and Andrew Symonds were part of the team - the latter, like Miller, able to slip between seam-up and offspin. In the years that followed, when O'Keefe and Lyon played together, Hilton Cartwright and Mitchell Marsh were in the side.

Green, however, has given them something there has rarely been in Australian Test cricket: a No. 6 who can also hold his own as a fast bowler.

"We hope we aren't going to play without Cameron Green very often," Labuschagne said. "Think it shows clearly the hole that he leaves in a side. I know he said that he feels he didn't play that much of a role [earlier in the summer], but as soon as you get rid of him you are like, geez, two and two bowlers, that's a bit different, we aren't used to that."

Australia are hopeful that Green will be available from the start of the series in India, but that is still not certain. And even if he is, the preparation may not have been ideal. Before the SCG game, Cummins said there was a strong connection between this game and India; the two-and-two combination could well be the likely route should Green not be ready for Nagpur.

"It's a luxury we have [ahead of India]," Cummins said of the twin spin option. "This [pitch] is probably as close as we're going to get to India here in Australia. It'll be good to see Ash [Agar] have a go after a little while and Matt [Renshaw] as well."

Labuschagne did unfurl his medium-pacers earlier in the season when Cummins was absent from the second innings against West Indies in Perth, but as much as he clearly enjoys it, he is unlikely to be seriously adding to Australia's seam options even though all the part-timers in Australia's order are spinners.

"It's something that happens by accident, it's not something we are actively pursuing," he said. "It's a bit more of a helping aid if we lose a bowler, I can make sure I can do a job to make sure I can rest the quicks."

So far, by winning the toss and laying a solid platform, Australia's selection decisions have fallen their way, but for a type of side rarely seen on home soil a fascinating four days still lie ahead.