Australia's coach Darren Lehmann has conceded the national team will need a fresh, more aggressive approach to be able to contend for next year's 50-over World Cup in England, following 12 months of poor results for the ODI set-up.

As the Twenty20 team shows the benefits of fresh bodies and minds in the current triangular series, Lehmann said discussions about the ODI squad were advancing quickly with little more than 20 games left between now and the global tournament in 2019. Australia's next 50-over assignment will be in England in mid-year, and Lehmann indicated he wanted to see the national selection panel nail down a squad to keep together from that point until the global tournament begins.

Warner given brief respite from T20s Two nights in your own bed may not sound like much, but Australia's coach Darren Lehmann is hopeful a "mini-break" for David Warner will rouse the stand-in Twenty20 captain from a run of low scores for both the pointy end of the triangular series and the Test tour of South Africa to follow it. "We're going to let him go home after the Allan Border Medal for a couple of days and just arrive the day before the game," Lehmann said of Warner, who will stay in Sydney for two days before flying to New Zealand on Thursday ahead of Friday's next match. "Give him a couple days at home really. It's always a challenge when you've got the schedule as it is, but David's really keen to play as captain, so we'll give him a couple days off and get him to New Zealand just before the game and he can play. "You've got your leaders in Steven [Smith] and David and you need one of them to captain, so that's the reason behind it from the selection panel, making sure we've got constant messaging through our leaders and David's been great in this series. Steven's had his break, David will get a little mini-break, and Steven's got to do the tour game while we're playing the [T20] final. "You can only do so much work. He's been working so hard it's almost like give him a couple days away from the game. Ricky Ponting's been doing some really good work with him. So we expect him to come out of that rut pretty quickly."

In an admission that the Australian team had fallen behind in terms of batting tempo, Lehmann said that the likely flat pitches and small grounds for the World Cup in England would necessitate a greater level of aggression with the bat, not unlike that used by Eoin Morgan's team over the past two years. This is a significant shift from Lehmann's declaration, following Australia's elimination from the Champions Trophy, also in England last year, that "when they win a World Cup, we can take the way they play".

"The results are more about execution for us. We had to chop and change a lot of the side depending on what's happening with the Test arena and going from Test to non-Test and obviously Tests are a focus for us," Lehmann said. "So we haven't been able to have a settled one day side. I'd like to see us play with a settled side over six months and see what the result is then, see how we play.

"[Team approach] will change in the fact you've got to be more aggressive in England because of the wickets, but then it can be overcast and swing, so you've got to have both ways covered for England as we've seen, you can play a certain way but you've got to be able to change, depending on what the pitch is and the conditions above."

He also indicated that the physical and mental toll of the preceding Ashes series had underlined how carefully Lehmann, the captain Steven Smith and the selectors would have to be about managing resources over the next 18 months, amid the competing priorities of Tests, the run-in to the 50-over World Cup and also efforts to raise Australia's international Twenty20 standing ahead of hosting the World T20 in 2020 - after Lehmann's tenure as coach is set to end in late 2019.

"They were pretty tired by the end of it," Lehmann said of the Test players who backed up the ODI matches. "We certainly didn't win the crunch moments in that one-day series, we had opportunities in every game and in the past our one day format we've scored those extra 30-40 runs and taken earlier wickets. We didn't do that, guys were a little bit tired and down I suppose, excited by the result of the Ashes, but didn't perform as well as we'd like in the one-day format. So that's another area we've got to look at and how we go about it.

"[The improved T20 performance] gives you food for thought after a long, tough Test series... fresh guys coming in. That's been exciting for us as a coaching group, the way they've gone about it has been pretty special so far. It gives you a lot of thought moving forward and that's a great thing.

"We'll sit down at the end of the South African series [to review], but we've always got to look forward. World Cup's coming along pretty quickly, I think there's about 22 games to go before we play our first game. So we'll have to settle on a group of players, we think we've got a really good group, it's just where we fit in, how we look, the style of play. We know what England's going to produce in terms of pitches, they're going to be pretty good, so it's going to be a pretty high-scoring World Cup, so we'll have to look at that."

To that end, the power hitting of Chris Lynn looms as a key part of Australia's plans, more than likely batting at No. 3. Lehmann said he wanted to see Lynn, who rejected a Queensland state contract last year to concentrate on T20 tournaments, play in all forms for his state, particularly once his lengthy rehabilitation from shoulder surgery returns the joint to full strength and health.

"You'd love to, yeah," Lehmann said when asked whether he wanted to see Lynn play the domestic 50-over tournament this year. "It just gets down to fitness with Chris at the moment. His shoulder is getting better, and we hope he plays as much cricket as he can in all formats. He's exciting as we've seen, he missed out in the second game, but first game he came out and took the game on.

"This game on Saturday, he took the game on and took it away from England, so he's an exciting talent. He's getting there, within three or four months I think he'll be back with his shoulder and more confident with what he's doing .It's getting better each and every day, it's just a time factor with this shoulder."

Another player who has resumed his central place in Australia's limited-overs plans is Glenn Maxwell, after a summer in which he has been the centre of much discussion about his role and relationships with Lehmann and Smith in particular. "He's finished games off for us and won us games, and that's what we've been asking for and he's delivered on the big stage for us, it's been excellent the way he's gone about it," Lehmann said of Maxwell's T20 displays.

"His preparation has been excellent and the way he has actually played, put more responsibility [on him] batting at No. 4 in the T20s and he's been exceptional. It seems like he's taken the knocks really well and come back and proved his point. Now we just want him to continue that and be really consistent, and I'm sure he will be."

Lehmann also indicated that the move of Aaron Finch down the T20 batting order to leave D'Arcy Short as an opener would likely continue, given the older man's strong recent IPL record in the middle order and the large number of opening batsmen in the team. "His record in the IPL batting Nos. 4 and 5 is unbelievable so we wanted to shape up and see how that looks like," he said. "D'Arcy's been very good for us at the top, so I think we'll continue with that, in the short-term anyway."

Looking overall at the home summer, Lehmann said that the ODI series had been the only disappointment in between a comprehensive Ashes series win and positive steps forward for the T20 squad, which will depart Australia for New Zealand on Tuesday in the same week the bulk of the Test squad will travel to South Africa for next month's four-Test assignment.

"It was an unbelievable summer. Record crowds, record viewership," Lehmann said. "You've got to win the Ashes at home, that's the biggest thing for us. One-dayers were a little disappointing as we know, T20s have been exciting, but overall you'd be pretty happy with the summer I would've thought. I know the fans have enjoyed BBL, the one-dayers, the whole lot. From our point of view, it's been exciting times and exciting cricket."