Steve Smith expects Matt Kuhnemann will pass all tests on his bowling, saying he was "surprised" when told the spinner's action had been reported.

Kuhnemann will undergo biomechanical testing on his action in the next 10 days, after match officials labelled it suspect during the second Test against Sri Lanka.

Australian officials have remained tight-lipped on the details of the test, but it's expected Kuhnemann will be able to undergo the examination in Brisbane.

The spinner will be asked to complete several hours of bowling, with markers attached to his arm and in front of several cameras and ICC experts.

Kuhnemann will need to bowl with similar speed and ball revolutions to what he did in Sri Lanka, while showing his arm does not straighten more than the permitted 15 degrees.

The 28-year-old is still able to line up for Tasmania this week in the Sheffield Shield, with ICC rules only precluding him from playing international cricket.

Australian players and officials remain perplexed as to why Kuhnemann's action had been reported now, given he has played 124 professional matches since 2017.

Kuhnemann also played two ODIs in Sri Lanka in 2022 and three Tests in India in 2023, before taking 16 wickets at 17.18 in Australia's Test series win in Galle this month.

"It's come as a bit of a surprise to me," Smith, who captained Australia against Sri Lanka, said.

"He has been playing for eight years in professional cricket and nothing has been said in that amount of time.

"I am thinking of him, at present, he has to go through the process.

"We're confident he will pass. He will go through that process back home, we wish him all the best."

If Kuhnemann's action is deemed illegal, he would face a race to clear himself in order to return for Australia's three Tests against the West Indies in June and July.

Touring teams regularly take an extra spinner on tours of the Caribbean, playing two tweakers if surfaces are drier.

Australia will also desperately want Kuhnemann back firing for the 2027 tour of India, given the left-armer's point of difference and ability to complement Nathan Lyon.

Smith said he had only learnt of Kuhnemann being cited after Australia's second Test win in Galle, and did not sense any issues during the series.

It comes as CricBuzz reported this week Sri Lankan players had raised concerns over Kuhnemann's action in the Test series, before umpires referred him to the ICC.

Sri Lanka players were said to have spoken to their spin bowling coach Piyal Wijetunge, who defended Kuhnemann and believed their concerns were due to the left-armer's unique wrist action.

"There were a few deliveries through the series though that didn't quite feel right," an unnamed Sri Lanka batter told CricBuzz.

"What we don't understand is why the match officials, who were the same for both Tests, waited until the series was over before reporting his action."