The coach with most experience converting NRL stars into gun rugby union players doubts Israel Folau has enough time to make the Wallabies team for next year's British and Irish Lions series.
Ewen McKenzie oversaw the transition of Lote Tuqiri, Mat Rogers and Mark Gasnier to the 15-man code, and also coached Wendell Sailor in his final two seasons in rugby at the NSW Waratahs.
McKenzie expects Folau to make an impact in rugby but believes the time it takes to adapt will put him behind the eight-ball for an instant Wallabies' call-up.
"The aptitude for picking the game up is the biggest test and it's not always easy from my experience," the Queensland Reds' director of coaching said.
The Waratahs will play 15 matches before the Super Rugby season breaks for the eagerly-awaited three-Test Lions series in June.
But Folau, an international three-quarter in rugby league before his two-year AFL stint with Greater Western Sydney, faces stiff opposition to gain a starting berth, especially for their season-opener against the Reds on February 23.
Standing in his way are Wallabies outside backs Adam Ashley-Cooper, Drew Mitchell, Lachie Turner, Rob Horne and fullback-flyhalf Berrick Barnes.
Added to that, Reds' flyer Digby Ioane and Rebels' duo Kurtley Beale and James O'Connor are automatic backline selections for Australia.
"Anything is possible, (Folau) is a good footballer, but you have to work out the position and the positional detail - that will be the challenge," McKenzie said.
"Plus they've got some pretty good incumbents there, they've got Test players in those positions and I don't know who will be putting their hand up to sit on the bench and not be involved so we'll see how they handle all that.
"The good news for us is we've got them in his first game. We're looking forward to welcoming him at Suncorp Stadium and that should get a few more bums on seats and we'll know how good he is in the transition."
Turner welcomed Folau's signing and denied the NSW backs were scared by the former Kangaroo winger's arrival.
"We've got to make sure that we put ourselves in the best position to win that spot."
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