Root still working out the England team he wants

Just add water. If the recipe for Ashes success is as simple as that then Joe Root's England side will find all the sustenance they need in the final Test of the series against South Africa.

Weeks of incessant rain in Manchester have left the outfield saturated and the pitch an unknown quantity. It is here that England must first strive to secure their first home series win against South Africa for 19 years, but as they do so preparation for the Ashes will never be far from anybody's mind.

Such is the state of the Old Trafford outfield that Root embraced suggestions that fielders might have to tread warily lest they picked up the sort of injury that put Simon Jones out of the Ashes series in Brisbane in 2002 when he ruptured an anterior cruciate ligament.

Last year, the same concerns were raised because the outfield had been heavily sanded after concerts at Old Trafford by Beyonce and Rihanna. This time there have been no pop stars on show quite so close to the match, although the outfield is doing a decent impression of Wet Wet Wet.

"It is about being street-smart with it," Root said. "The outfield is not going to be 100% and we will have to be quite clever about things. It is difficult to tell people not to play with 100% in Test cricket.

"Whether they go about it slightly differently is up to them. It is definitely important they are made aware of it and there are no unnecessary injuries that occur."

England might be 2-1 up in the series, but they do not yet have a settled Ashes line-up that they can imagine slapping down on the match referee's table ahead of the first Test in Brisbane on November 23.

Of the two batting debutants at The Oval, Tom Westley has made a good first impression at No. 3 and now must cement that impression both here and in the three Tests against the West Indies later in the summer. Dawid Malan has much more to prove after his dominant off-side game did not reap rewards at The Oval. There also remain significant question marks over Keaton Jennings as Alastair Cook's opening partner.

Root accepts that "it is very difficult to work out" precisely what England's best line-up is and hopes "over time that should become a little bit clearer." One pragmatic argument for playing an extra batsman, and again omitting Liam Dawson, is that at least it leaves room for more Ashes batting auditions. The unsettled weather, in any case, suggests that Dawson will not force his way back into a side that won so impressively in south London.

"I think from this series there are a few guys who have really stood up and put their name in the hat for the future," Root said.

"It is all about backing up performances. You know what it is like: sometimes you can have a really tough series and all of a sudden the scrutiny is on you. That is the world of Test cricket unfortunately and it is about trying to be as consistent as you can.

"The majority of the top 7 or 8 is pretty settled so that is nice to know. Ideally you want to get the other slots nailed on so. We have to make sure we are doing everything we can to give those guys the best chance to nail those spots down."

Root was doing a lot of nailing down in his captain's media conference. Some wonder whether his discussions with England's coach, Trevor Bayliss, over the balance of England's side in the Ashes could yet become a bed of nails.

Bayliss makes no secret of his belief that England are better balanced with the likes of Dawson - or even Adil Rashid - in the top eight. Root was granted an extra batsman at The Oval and the upshot was a 239-run win, but he might press his case more vehemently on Australian pitches.

"Early on in my captaincy I am trying to find out what I want and what works and what's going to be the most successful formula moving forward," Root said. "I suppose it's very difficult to use Test matches as experiments but it's important to find out what works early on so you have the opportunity to be more consistent and more successful.

"You are trying to get the balance right between that consistency and making sure that we are playing a side that suits the surface that we come up against. Moving forward that is something we will have to get nailed down before we go to Australia. Hopefully we will stumble across it very quickly."

One aspect of England's performances in the last two years has been their relative weakness when batting second, and facing a substantial opposition score. It would be no bad thing in road-testing the development of their side for that to happen in Manchester.

Root suggested that, in an odd sort of way, this had happened at The Oval, with the need to respond arising not from a large opposition score but the hammering they had taken in the media for their reckless batting approach at Trent Bridge.

"It's a slightly different response because it is not a response to a score set by the opposition, but we wanted to set things right and respond to the mistakes we had made in the previous game. It's important that we drive that forward and it's not just a one-off thing."

England's resolve grew from the first-day example set by Cook. "A lot of that was down to the example Cooky set at the top of the order: - he played with a lot of determination and grit," Root recognised.

At Old Trafford, where it will be an optimistic batsman who imagines the sun beating down on a golden surface, it is down to others to capture that mood.