It says a lot about the challenges Justin Langer has faced in his short time as Australia coach that he admitted to having sleepless nights ahead of the Gabba Test against Sri Lanka, knowing the pressure the team were under not to be beaten at a ground that has become a banker for victory.

Langer also worried about how the decision to parachute Kurtis Patterson into the squad three days before the Test, then hand him a debut ahead of Will Pucovski, would be received in a season where Australia's selectors have often appeared confused and uncertain.

In the end, neither of Langer's fears came to pass with the team securing an innings-and-40-run win to maintain an unbeaten record in Brisbane which dates back to 1988, and though Pucovski's omission sparked debate Patterson looking at home on debut with a neat 30 and four catches, the last of which was a blinder in the gully to remove Dilruwan Perera.

"I kept thinking before the game, imagine if we get beaten by Sri Lanka at the Gabba. That's why I haven't slept much the past week. Hopefully I'll sleep a bit easier tonight," Langer said.

He knew the late inclusion of Patterson, following his twin hundreds in the tour match, would divide opinion especially as it meant 20-year-old Pucovski was sidelined once the experience Joe Burns was also preferred in the final XI.

"We decided and it was controversial. To see how it would be received from the public picking someone from outside the [squad], spoke to a few people I trusted about it and we just felt it was a really common sense thing to do. You agonise more probably at this point of the season about what's going to get reported on, if I'm completely frank. Hopefully I'll get tougher over the years that way and won't think about that.

"He got 100 in both innings against Sri Lanka and you talk about rewarding performance. So when it came down to that, although we'd selected the squad before, I was really glad we had the courage to have that flexibility and bring someone in from outside that original squad."

Langer gave a strong endorsement to an unchanged XI for the second Test in Canberra - although he was speaking before Marcus Stoinis' call-up was confirmed and did say conditions would have to be assessed - which means Pucovski will likely have to wait his turn. The 166-run stand between Marnus Labuschagne and Travis Head was Australia's highest since the final Test of the 2017-18 Ashes and has earned the pair some breathing space even though both missed hundreds.

"Marnus and Travis Head's partnership was significant. Both threw away an opportunity to score 100s," Langer said. "The best way to learn how to make hundreds is to make hundreds, so they know they missed an opportunity yesterday. I thought Kurtis Patterson looked like a Test batsman."

Though it was pace bowling which dominated the Test, Langer was impressed by the work of Labuschagne and Head against spin on a surface which offered turn and bounce.

"More than just the runs, [Marnus] had good footwork, he plays spin really well. I thought he played the spin so well. He plays almost like an Indian batsman, he gets back, uses his feet, and uses his hands [to get the ball] into gaps, uses the sweep shot well, gets down the wicket.

"I think Heady hit one loose shot and it was almost like, 'oh snap, that's right, everything I've been talking about'... and then he let the ball come to him and he looked like a really good Test player. The thing that's most impressive about Travis is how he keeps learning, keeps getting better. The way he's playing spin from a year ago, his forward defence against offspin, the way he's able to come down the wicket, he's improving all the time and that's all you can ask for."

There was also backing from Langer for the struggling senior pair of Usman Khawaja and Mitchell Starc. Khawaja fell for 11, bowled for the third time in the last three balls he'd faced from Dilruwan Perera in Test cricket. Starc managed his 200th Test but he was the least impressive of the attack following on from an underwhelming finish to the India series.

"I suppose there's high expectation on Mitchell but he's a very good player and is really important for our team. Same with Usman. He still averages 40 in Test cricket. He's our most experienced player. He's very calm. He brings a lot of calmness and composure and experience to the group, so we're happy with the way he's going at the moment."