White-ball specialist batsman Aaron Finch and South Australia captain Travis Head will make their Test debuts in the series-opener against Pakistan in Dubai on Sunday, Australia coach Justin Langer has confirmed.

Both players scored half-centuries in Australia's drawn tour match against a Pakistan A side, convincing Langer to award them their first caps in the five-day format.

"There was never any doubt over those two for me, I thought they were certainties to play," Langer said of his first test side as Australia coach after the former opener took over from Darren Lehmann in May.

Despite the pair making certain of selection, doubts remain in other areas of captain Tim Paine's team, with opener Matt Renshaw picking up a head injury after being struck by the ball during the tour game that ended on Tuesday.

"I think Matthew Renshaw will be physically fine -- the one thing he's got is he hasn't played much cricket," Langer told reporters in Dubai.

"He went on Australia A trip, he got a hamstring strain... he hasn't spent much time in the middle. That's going to be the issue for him.

"It's going to be an instinct call. We've got to weigh up what he's done in the past. He's obviously a very good young player. We've got to work out whether he's spent enough time out in the middle to be ready for a test match."

Renshaw's possible absence could pave the way for South Africa-born Marnus Labuschagne, who came in at number six against Pakistan A and scored an unbeaten 39 in Australia's only innings.

The 24-year-old, who can also bowl part-time leg spin, was a surprise inclusion in the 15-man squad but played a key role in Queensland's Sheffield Shield triumph earlier this year.

"We've seen in the history of Australian cricket a lot of people take their opportunities through injury," Langer said.

"I thought Marnus fielded brilliantly but was really good with the bat (against Pakistan A), bowled a few overs. He's certainly put a strong case forward for selection as well."