There will be no bat-off for the final batting spot in Australia's side for the first Ashes Test at the Gabba, despite both Usman Khawaja and Travis Head being named in the 15-man squad.

The two men will face each other in a Sheffield Shield contest starting next week in Adelaide and are set to play in Australia's three-day intra-squad game in Brisbane on December 1. But chairman of selectors George Bailey confirmed that the selection panel was already leaning towards one of the two for the final middle-order spot, which Matthew Wade had filled when Australia last played Test cricket, back in January.

"We're leaning towards one of them," Bailey said on Wednesday. "But, you know, the whole purpose I guess of naming a squad is to have a squad there. So, we'll work through that much closer to the start of the first Test."

Bailey joked with the media on Wednesday, holding firm as he was pressed to name one of the two left-handers for the opening Test. "No," Bailey said when asked which player he favoured. "You'd have nothing to write about tomorrow then. I want to see where you guys lean. Have a crack at it. It'd make the Shield game much more exciting next week."

Khawaja has the hot hand coming off Shield scores of 174, 119, 70 and 8 in his last three matches. He did receive a huge slice of luck in that 174 against South Australia when he should have been given out caught at gully on 13, but thereafter he has been in sublime touch. His 70 out of 129 on a green day-one pitch at the Gabba against Ashes squad member Jhye Richardson was as good as any domestic innings played this summer.

Head started this season with 163 in a Shield game and 230 in a 50-over Marsh Cup game, but both came at the batting paradise of Karen Rolton Oval in Adelaide. Since then, he has returned scores 55, 23, 9, 21, and 14 at three Test venues, but Bailey was not concerned about his form.

"You never want to be trying to pick someone out of form, but I don't think there's a body of evidence to suggest that Travis is out of form," Bailey said. "I actually think they are both still batting beautifully."

Khawaja will turn 35 in December while Head will turn 28. Bailey did note that the age difference was hard to ignore completely, but felt it was not a major influence on their decision-making.

"Try not to," Bailey said. "There's no doubt that's one of many, many factors. But I think certainly for the here and now of winning this Ashes series, it's not particularly relevant."

Harris will open with Warner
Bailey ended any speculation around Marcus Harris' place at the top of the order, confirming that he would open with David Warner.

"I really like Marcus Harris," Bailey said. "He's done everything that we're asking in terms of scoring a mountain of domestic runs. He's gone away, he's had a really good, strong winter playing for Leicester as well. So he just continues to do all the right things domestically.

"We'd love nothing more than being able to back him in and give him an extended run up at the top of the order. We know how important opening partnerships are, trying to forge a really strong relationship with Davey at the top is really important for our Test team."

It means the intra-squad game will not be used as a Hunger Games-style trial as it was ahead of the 2019 Ashes series, when Cameron Bancroft came from the clouds to work his way into the first Test side after not being initially selected in the Australia A squad that toured England prior to the Ashes.

"The squad is locked in," Bailey said. "I don't envisage that game being used as a selection tool. I think it's very much about preparation."

No place for Mitch Marsh
That means there is no room in the Test side for Mitchell Marsh despite his stunning T20I form that culminated in a Player-of-the-Match performance at the World Cup final. But he has been named in the Australia A squad.

"I think T20 and Test cricket are about as far removed as you can get from a cricket format," Bailey said. "So we've just got to be really careful about necessarily assuming that the one will lead to the other but what I said about Mitch the other day, and I'll say it again, is one, just how thrilled we are for him to have had the World Cup that he did and obviously to finish with the game he did in the final was just superb, and great reward.

"I think we should be seeing the best of Mitchell Marsh for the coming years. So really excited about what he can produce, and we know he can play at the Test level."

Another man who is missing from both the Australia and Australia A squads is Moises Henriques. He was picked in Australia's last Test squad that was due to tour South Africa before the tour was abandoned and played in all 13 of Australia's T20Is and ODIs in the two tours of the Caribbean and Bangladesh. But he hasn't been able to play any domestic cricket so far this summer due to a late arrival home from the IPL to avoid quarantine.

"I've been in good contact with Mo," Bailey said. "He knows that not being here as part of the A squad is not necessarily the end for him. We know he's a quality player and he's been particularly consistent."