Australia coach Justin Langer is confident Glenn Maxwell is close to "a very big score" despite two single-figure innings to start the tour of England which follow on from a lean IPL, but admitted he faces some tough selection decisions before the first ODI at The Oval.

Maxwell made 1 and 3 in the two warm-up matches against Sussex and Middlesex, falling to spin on both occasions, but Langer called his work behind the scenes as "literally outstanding" as he aims to cement a return to the ODI set-up. Maxwell did play the final ODI against England at Perth in January - making 34 - having been left out of the original squad, and after his omission then captain Steven Smith said that Maxwell needed to train smarter. Since then there has been upheaval in Australian cricket.

Smith and David Warner are serving suspensions that run till just before next year's World Cup while Mitchell Marsh is currently nursing an ankle injury which means there is a chance for others to stake claims for long-term berths.

However, early in the England tour, Maxwell has been the least convincing of Australia's batting options that have been given a chance. Langer admitted the lack of runs was a concern but believed that he will come good.

"He is [a worry] but that said I have been super impressed with Glenn Maxwell, his preparation has been literally outstanding. I would be very surprised if he doesn't get a very big score very soon.

"There's been a lot of talk about Glenn Maxwell but I have been incredibly impressed with the way he goes about his business and even the way he has been batting in the nets. He played at Whitgift School a week ago [an inter-squad match] and he was the man of the match that day. I am sure a big one is not far away from him."

Langer also hoped that the imminent arrival of Ricky Ponting, Maxwell's IPL coach at Delhi Daredevils, to join up with the coaching team - he arrives on Monday and will work with Australia between commentating commitments - will be a boost to him.

"To have the influence of someone like Punter is gold…so if he keeps preparing well and keeps trusting his preparation it is not far until he becomes an absolute star, I think. He's got so much talent. He's working as hard as anyone," Langer said.

Despite Langer's strong endorsement of Maxwell, there could yet be significance in his excitement over the potential of having Marcus Stoinis and Shaun Marsh at No. 3 and 4.

Different combinations of the top order were used across the two warm-up matches and Langer hinted that Aaron Finch's role at No. 5 against Middlesex - where he made a run-a-ball fifty - could yet be his role against England as a solution is sought for Australia's middle-order issues. Travis Head, who took Finch's position at the top, also scored a century. All of that could leave a choice between D'Arcy Short's potential as an opener and Maxwell's in the middle order.

"I love the idea of Shaun Marsh and Marcus Stoinis batting at three and four. They're like two gladiators aren't they, they're big strong boys, we know they can get hundreds, we know they can bat for a long time," he said.

Michael Neser took a sharp caught-and-bowled Getty Images

"Aaron Finch's record opening the batting for the last five or six games for Australia, and against England, is just brilliant. It's hard, but the way he batted [at Lord's], one of the areas we need to get better at over at least the last year or so is in that middle order. Particularly against spin. We're all aware of it. He's as fast as anyone between the wickets, which is a key focus for our one-day cricket. He's fearless. He actually changes momentum of the game. There are plenty of options and I'll have bags under my eyes by Wednesday trying to work out the best."

Then there's the make-up of the attack. Langer was encouraged by the experiment of going with an extra bowling option in the warm-up matches which could tip the balance towards those who offer a little extra batting ability. The uncapped Michael Neser, a late call-up to the squad to replace the injured Josh Hazlewood, is a chance for a debut after two promising warm-up outings.

"I've always seen having that extra bowling option work well in domestic cricket, particularly if your seven and eight can bat a bit and we've seen that with Ashton Agar and Michael Neser, they can bat a bit. I think Jhye Richardson has got some talent as well with the bat. They've all made our job as selectors really hard. It's a headache.

"I'll guarantee now I am not going to sleep for the next two nights working out what the best XI is going to be for the first game.

Nathan Lyon and Alex Carey, the reserve wicketkeeper, are the only two members of the squad who weren't given a chance in the two tour matches and Langer confirmed it was unlikely either would feature at the start of the series unless The Oval suggested a pitch that would significantly favour spin - which would give Lyon a chance of starting.