South African legend Dale Steyn has warned Australia against dropping out-of-form opener David Warner, labelling him "one of the best batters I've ever bowled to" who will rediscover his best form this summer.

Test cricket's fifth-most prolific fast bowler, Steyn believes Warner's horror Ashes campaign in England will prove to be an aberration, while he's also heaped praise on Steve Smith following his record-breaking return to international cricket this year.

The spotlight during this week's opening round of the Marsh Sheffield Shield will be on Australia's top-order batsmen, including Warner after he averaged just 9.5 in the Ashes and fell under the spell of England quick Stuart Broad.

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On Tuesday, head selector Trevor Hohns said "the slate had been wiped clean" after the Ashes, but he refused to guarantee Warner would retain his spot for the first Test of the summer.

Warner averages almost 70 in seven Tests against Steyn, and the South African is in no doubt the left-hander will quickly return to his best.

"He's one of the best batters I've ever bowled to," Steyn said after he signed on to play with the Melbourne Stars in this season's KFC Big Bash League.

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"He puts you under pressure from bowl one on day one of a Test match.

"You have to take what he can give you with what can happen. In this case, he's been found wanting around the wicket against someone like Broady attacking that off stump. Sometimes that can happen.

"But he'll get to Australia, he'll find some form, he'll be playing around his mates and around his home crowd and that can quickly change for him.

"World class players don't become rubbish overnight, especially over one tour.

"He'll be fine, I wouldn't drop him at all. I'd leave it as it is."

While Warner floundered in the Ashes, Smith took his game to new levels in what was the pair's first Test campaign since the Cape Town saga 18 months ago.

Steyn cheekily pointed out that he's the only bowler to have dismissed the world's top batsman for a golden duck in Test cricket, trapping Smith LBW first ball during a memorable spell of bowling in Port Elizabeth in 2014.

Steyn celebrates Smith's wicket at Port Elizabeth in 2014 // Getty

But the Proteas legend, who retired from Test cricket earlier this year, quickly added he's in awe of the 30-year-old Australian, whose homespun technique continues to confound the world's best bowlers.

"When I bowled to batters like Michael Vaughan or Jacques Kallis who (were) classical, technically perfect, sound batters, I always found that I could get them out," Steyn said.

"It was only the weird guys that came around, like Shiv Chanderpaul and Steve Smith, they really confuse you about the line you should be bowling. Whether that should be on the stumps (or) outside the stumps.

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"Steve has come … and with his technique that he's naturally developed, he's just confusing bowlers left, right and centre.

"They literally don't know where to bowl to this guy. And while they're trying to work that out, he's clubbing them all over the place and scoring runs at the same time.

"He's just in a league of his own right now and I'm very happy that I don't have to play Test matches against him ever again.

"He's wonderful, he's got a great eye and a very difficult and weird technique to work out, which is working for him beautifully.

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"I think he's a marvellous player."

Warner and Smith will return to Shield cricket in a star-studded clash against Queensland in Brisbane from tomorrow, with Mitchell Starc, Usman Khawaja and Marnus Labuschagne to also feature in the match at the Gabba.

The first Test of the home summer, the first of two matches against Pakistan, starts at the same venue on November 21.

Queensland will host NSW in the Marsh Sheffield Shield opener at the Gabba from 10am local time (11am AEDT) from Thursday, October 10 with a free live stream via cricket.com.au and the CA Live app, including Apple TV.

Queensland squad: Usman Khawaja (c), Joe Burns, Cameron Gannon, Sam Heazlett, Charlie Hemphrey, Marnus Labuschagne, Michael Neser, James Peirson, Matthew Renshaw, Billy Stanlake, Mark Steketee, Mitch Swepson.

NSW squad: Peter Nevill (c), Sean Abbott, Nick Bertus, Harry Conway, Trent Copeland, Liam Hatcher, Moises Henriques, Daniel Hughes, Nick Larkin, Steve Smith, Mitchell Starc, David Warner.