Australia's search for their best starting XI this World Cup continues, according to assistant coach Brad Haddin. Australia are comfortably placed with four wins and a loss to India, but there's a sense that a few of the wins haven't been entirely convincing. Then, there's also the absence of Marcus Stoinis - injured - that hasn't helped team balance.

"At the moment we're still trying to find that best XI," Haddin said. "Marcus has thrown a spanner into everything there with his injury and how important an allrounder he is. We're still trying to find what best works for us. Come later in the tournament, we'll start to understand what the conditions are like a lot better and what is our best XI."

Haddin also admitted while it wasn't yet a matter of concern, they've spoken about the need to be flexible at all times if they are to win a sixth World Cup. "The players understand that and we're training them accordingly," he said. "I think one of the luxuries at the moment is we're still winning, and we still haven't found the perfect rhythm for our game, which is a dangerous sign moving forward."

It's not just about the healthy headaches. There's also an issue surrounding the lack of certainty around batting roles. Usman Khawaja, for example, has mostly alternated with Steven Smith at No. 3 and No. 4. He also dropped to No. 6 against Pakistan. All this despite establishing himself with runs at the top of the order while David Warner was serving his one-year ban for ball-tampering.

Australia have generally relied on a right-left combination to follow the openers, but Khawaja has struggled for rhythm lower down the order; his effectiveness not at the same level as it was while he was opening. Haddin, though, insisted the team management is happy at where he's at.

"He's playing a different role. It's not that he's not having success, he's been in a role where he's had limited opportunities," Haddin explained. "Before, he could go out and set the pace of the innings and now the innings is dictating the role he needs to play.

"He's been okay with it - he's a class act. We're pretty happy with where he's at - he's just got to bat the situation, and No.3 is not uncommon to him. He's played most of his career at No.3 in state cricket and Test cricket."

Australia are also posed with the question of just when is the right time to send in Glenn Maxwell. He was promoted to No. 4 against Pakistan but has batted a position lower in the other games. An undefeated 48 against Sri Lanka has so far been his best score in the tournament.

"The one thing we've found with Glenn is he's an explosive player and as you've seen [against Sri Lanka] he can turn a game very quickly by himself, but he's also got to fit into what's best for the team at that time," Haddin said. We've moved him up and down, and that might look like nervous decisions that we're making, but we've spoken about them a lot before.

"It's not a shock that he's moving up and down the order, and all the players understand that. He's pretty confident as well. I don't think it'll worry him."

Australia will be encouraged that despite these issues, they have still been able to win. But they don't want to have unanswered questions into the next phase of the tournament.

"What we're doing at the moment is some really good signs in tournament play," said Haddin. "There's some signs out there we're doing some things really well, and some signs that we need to work on things."

"It's important we get to these bigger games and see where we really are leading into the back-end of the tournament. It's sort of panning out how we expected in tournament play."

"Now is a really exciting time in the tournament - a run against some of the top nations that are playing some really good cricket. It's exciting to see where we're at and hopefully as we get deeper into the tournament we'll know which is our best XI."