Australia coach Justin Langer has cast doubt on Steven Smith's return for the deciding ODI against England just a few hours after sounding confident he would be able to take his place following the blow to the head he suffered before the opening game.

After having a net at Old Trafford on Tuesday, Langer said that Smith looked "a bit rusty" and he was less confident about bringing him back although a decision would not be made until shortly before the match.

"In terms of Smithy, he had a hit today. He still looks a bit rusty to be honest," Langer told SEN Breakfast with Pat and Heals. "We'll give him until the last moment to play but I'm not as confident now as I was 24 hours ago."

Some mystery still surrounds the circumstances in which Smith has missed the tourists' past two matches. He was struck on the side of the helmet by a throwdown during net practice at Old Trafford, and though Cricket Australia officially stated he had passed a concussion test, he was still required to go through a series of protocols before his net session on Tuesday. Following that net, a CA spokesperson confirmed that a final decision on Smith's availability would only be made on Wednesday.

Whatever the true extent of Smith's need to recover from the blow to the helmet, his inclusion would allow the Australians to have a far more versatile and reliable batting order for the final match, having fallen apart alarmingly in some adverse conditions against the pace and reverse swing of Chris Woakes and Jofra Archer in the second game of the series. Marcus Stoinis has deputised at No. 3 in the first two matches

"Fingers crossed. We know what a great player he is, he got a blow to the head in training the day before the first game, so we've been going through all the concussion protocols, he's definitely tracking in the right direction," Langer said when speaking before Smith batted on Tuesday morning. "We're hopeful he'll be right for tomorrow, but if he doesn't come up again, then like always we'll keep him healthy in mind.

"He was just practising, we talk about Steve, he was probably on his 30,000th ball, probably had two or three to go, and the wickets over here, the facilities have been brilliant, but they're a bit worn because of so much traffic through them over the past few months. One ball just didn't quite get up, he ducked into it and it hit him in the side of the helmet.

Langer spoke glowingly of how his players had responded to the challenges of an England tour with no meaningful cricket behind them, in addition to the constraints of the biosecurity bubble in which they have been thrust due to the coronavirus pandemic. However he said that the selectors remained on the lookout for middle order problem solvers to weather scenarios like those that have presented once each in the T20 and one day series.

"It's been disappointing, we've played such great cricket throughout this whole tour," Langer said. "You always look below the surface, how we've all played our cricket, all the guys have played their cricket from the moment we arrived with no cricket under our belts, it's been a real credit to the boys. Consistently across the board we've been really impressive. There's a few areas we need to get better at though, and that's part of becoming a great team.

"One is bowling in those last few overs, which is always the case, but also in our middle order. And we're not shying away from that. The boys were incredibly disappointed the other night and disappointed during the T20 series, but they're working hard on it.

"What do you look for? Problem solving. I think about the Dhonis and the Husseys and the Bevans, Jos Buttlers, the guys who finish it well, are great problem solvers, and they've got real confidence in their ability to, over and over, solve the issues which come up, whether you're chasing big scores, small scores, on different wickets, spinning wickets, wickets that are stayng a bit up down. that's what we're looking for in the middle order, guys who are able to solve problems and get the job done."

As far as the mental strain of the bubble itself was concerned, Langer said a key part of the exercise was not being overwhelmed by thoughts of occupying similarly restricted circumstances for an entire summer. "The biggest challenge for all of us is that it's a bit like scoring a hundred, you can't score a hundred unless you give the next ball 100% attention," he sad. "If we start looking too far ahead of ourselves, that becomes a real challenge.

"It's almost one day at a time...it's just when you start looking ahead to when we get home and then quarantine and how the summer looks and if you keep looking too far ahead, then it gets challenging."

As for the likelihood of most of his best players entering home Test assignments after a surfeit of white-ball matches in the IPL and then against India, Langer struck a time-honoured theme about the best players finding ways to adapt.

"It's something we're very aware of," Langer said. "Particularly as you think about the lead-up to this tour, straight to the IPL, potentially straight into some white ball cricket, and then the Test match, with it all pretty tight. Am I worried about it? Not really, we had a good dress rehearsal last year between the World Cup and the Ashes, the best players adapt and we've got some great players who might need to adapt. But when it comes to the colour of the ball, I'm really confident they'll be able to do that."