Australia's national selector Trevor Hohns has admitted to being "very concerned" about the lack of Test cricket the team will play ahead of the Ashes next season.

With the tour of South Africa last month postponed, there will be a 10-month gap between Tests when they are due to play Afghanistan in a one-off match in late November before facing England.

That game against Afghanistan could be the only red-ball cricket those players also involved in the T20 World Cup will have ahead of the Ashes due to the likely need to quarantine on their return from India.

For those not in the T20 set-up, Hohns expects there to be a decent amount of Sheffield Shield cricket available in the first part of the next season but he conceded it is not an ideal situation with England having a full Test season ahead of them at home.

"Very concerned about that, no doubt, and hopeful that they'll be plenty of Shield cricket - and I believe there will be - programmed leading up to the first Test," he said. "However, that won't help some of our players as hopefully they'll be fully engaged in the T20 World Cup.

"It's a difficult one, England are certainly playing plenty of Test cricket and we haven't got anything on the plate so it's a concern."

There will be at least two Test batting positions vacant leading into the next home summer following the announcement of a trimmed down central contracts list that only included three specialist Test batters - David Warner, Steven Smith and Marnus Labuschagne - along with allrounder Cameron Green.

An opening partner for Warner will need to be found - Will Pucovski will be the frontrunner if he recovers from shoulder reconstruction - along with a middle-order batter to fill the No. 5 spot which rotated between Travis Head and Matthew Wade against India, both of who lost their contracts.

"There's no secret that there are positions available whether that's middle order or the top of the list," Hohns said. "Yes, it is a concern because there's no standout but that's what we are challenging our players to really put their hands up at the start of next season then get into the Australia side and perform well when they do."

There may also be conversations about whether the bowling attack needs freshening up with Hohns indicating that rotation is likely to be forced on the fast bowlers to ensure they aren't flagging towards the end of the series as happened against India where Mitchell Starc, Josh Hazlewood and Pat Cummins played throughout alongside Nathan Lyon. While Green's introduction provided somebody to share the burden he did not take a wicket in the series.

James Pattinson was retained on the contracts list despite playing just four Tests in the last five years with Hohns terming him "our premier back-up fast bowler" although Jhye Richardson and the uncontracted Michael Neser will also come into contention.

The initial part of the new contract period will be heavily focused on T20 with the World Cup in October and a number of the players on the list are likely to only feature in white-ball cricket. Hohns said that the idea of offering separate white and red-ball deals had been floated but it was still some way off being an option.

"It's an interesting conversation and while we have mentioned that we are not quite ready for that yet, but it may progress to that down the track because it's becoming more obvious that players are specializing in the different formats. Certainly something to be looked at down the track.

"There's a little bit of focus on T20 cricket but we also try to make sure we remain focused on the fact that Test cricket to us, and hopefully to our players, is the prime form of the game. We see that as the top of tree, but there is a T20 World Cup coming up so we've had to cover a core group of players we think will feature in this list."