Pollock pinpoints England's Ashes weakness

Test legend Shaun Pollock believes England's top three is an issue as they finetune preparations for this summer's Ashes.

England lead their current Test series against South Africa 2-1, with the final Test beginning at Old Trafford on Friday, however they have achieved their lead without heavy contributions from opener Keaton Jennings.

Yorkshire's Gary Ballance was No.3 in the first two Tests and was another who struggled to make an impact, and while his replacement Tom Westley performed well with scores of 25 and 59 on debut, the question marks remain over England's top order.

"I think the struggle for England so far has been the top three, with the exception of Alastair Cook who's been good again," Pollock told Wide World of Sports.

"The others haven't really settled and I don't think the top order is set in stone.

"It's the area England will be most concerned about heading into the Ashes, because nobody has really put their hand up to partner Cook on a long-term basis.

"Unfortunately for England over the last few years there's been quite a few guys who've come in, had a taste and done alright, without being able to cement the spot."

England's 'other' opening spot has been a virtual revolving door since the retirement of Andrew Strauss, with more than a dozen batsmen handed an opportunity without a long-term solution being found.

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Jennings' form for England has been poor since his debut century in India last year, with the left-hander's scratchy 48 in the second innings at The Oval his best score of the ongoing series against South Africa.

Pollock said he had no issue with captain Joe Root staying at No.4 in the order, though he conceded it did contribute to the existing top-order dilemma.

"I don't have a real problem with it, Root seems comfortable at number four," he said. "Westley came in (at) The Oval and made a 20 and a 50 and he looked the part, so he might get a run there for a while.

"The lack of experience would be the concern, but at some stage you have to give them an extended run to try and cement their spots.

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"I'm sure in the ideal scenario they would like to be heading to Australia with a settled top five, but I think on the other side of the equation, they've got such a settled middle order that it might compensate for the inexperience at the top."

Australia look well placed to expose England's inexperienced top order, with an array of fast-bowling talent to choose from.

"If everyone is fit and raring to go the (Australia) bowling attack will be awesome," Pollock added. "There's a lot of depth with (Mitch) Starc, (Josh) Hazlewood, (James) Pattinson and (Pat) Cummins, and there's nothing better for teams than consistently having the opposition two down very early.

"It would be ideal if both sides bowling line ups are at full strength, because we could see the new ball attacks having a big impact on the series."