England won't win the Ashes unless their catching improves, according to coach Trevor Bayliss. He described his side's efforts as "terrible" during the Investec Test series against West Indies and suggested a lack of concentration could be to blame.

England dropped at least 14 chances in the three-Test series. While some of those chances were far from straightforward, there were several that were "quite easy" according to Bayliss. Alastair Cook, at first slip, was responsible for three of the drops, while Moeen Ali and Stuart Broad also missed chances they would normally have taken.

While England still proved strong enough to defeat an inexperienced West Indies side (who dropped around 10 chances of their own) 2-1, Bayliss knows the Australian side will not be so forgiving.

"The catching has been terrible, especially in the last couple of Tests," Bayliss said. "We're not going to go there [Australia] and win anything dropping that many.

"We were catching quite well up until the last three Tests and some of the catches we dropped we were quite easy. Dropping easy catches is usually down to concentration."

Ahead of the last Ashes series in England in 2015, Bayliss inspired a sharp improvement in England's catching. Taking them through some notoriously tough training sessions on a pre-series trip to Spain, it resulted in some outstanding catches - such as Ben Stokes' remarkable effort at Trent Bridge - during the series.

But Bayliss insisted there had been no let-up in the intensity of England's training and dismissed the suggestion that poor backdrops could be any excuse.

"We focus on it all the time," he said. "It matters all the time, not just in important series. That is the disappointing thing.

"It is not from a lack of practice. We are doing a little bit of technique work with some guys which sometimes can take a little bit of time to get a hold of.

"You work hard at it and they do it well for a while and then we go through a period where we drop a few and that seems to buck them up a bit. Some of the grounds in this last series haven't been the greatest viewing grounds but still they are professional players and they should be grabbing hold of some of those they've dropped."

Bayliss also admitted he was still not sure of the batting order for the Ashes. While he favours Joe Root returning to No. 3 in the line-up - Root prefers the No. 4 position - he also accepted there was a "big question" over whether the three new faces in the top five had "done enough" to retain their spots.

While he gave a strong hint that Mark Stoneman (who averaged 30 against West Indies) would be opening in Brisbane in November, the future of Dawid Malan (38.50) and, in particular, Tom Westley (17.75), is less clear. Gary Ballance, Haseeb Hameed and Alex Hales may also come into the selectors' thoughts in the coming days.

"That's the big question: whether the three guys we have been speaking about all summer have done enough," Bayliss said. "I am sure they would have loved as much as we would for them to come out and make a couple of hundreds and then there' nothing to talk about.

"Are they good enough for long enough? Are they tough enough especially for an ashes series. We will be discussing other players that we have had in the team over the last 12-18 months. But it will be hard to go past these three guys.

"Stoneman does look like a tough cricketer at the top of the order. His game is in good order and nothing much phases him. He's calm around the changing room, he has a good knowledge of the game and what works for him. He copped a couple of good ones during this series but he didn't let it worry him. He just came out and made some runs in some difficult circumstances.

"Malan missed out early and there was a bit of pressure on him. But he made a couple of 60s since, so he is very much in the running. And Westley, against South Africa, well, there weren't too many more difficult situations than that.

"I would always have Root at No. 3. He is by far our best player and personally I believe that is where your best player should be. I think he will end up at No. 3 at some stage in the future.

"He has done well at four and he feels comfortable at four. If that's where your best player feels comfortable and is scoring runs at number four then that's the other side of the argument: why change? So whether it's a three or a four, we still have to find someone who can do the job."