Australia off-spinner Nathan Lyon has launched a spirited defence of five-day Tests following the recent discussion around four-day matches, labelling the concept "ridiculous".

The debate around four-day Test cricket has reignited after Cricket Australia chief executive Kevin Roberts said CA would "look really seriously" at the concept in the coming years ahead of the next eight-year Future Tours Programme cycle from 2023.

Australia host Afghanistan on home soil next summer and Roberts said that CA would consider making that match a four-day contest.

Lyon says he is "totally against" four-day Test cricket and points out some of the game's most memorable matches have finished in dramatic fashion late on the fifth day.

"You look at all the big games around the world and some of the best Test matches I've been part of, they go down to the last day," Lyon said on this week's episode of The Unplayable Podcast.

"You look at (Australia) against India at Adelaide in 2014, that went down to the last half-an-hour on day five. Then you look at Cape Town in 2014 as well, you look at that Test match where Ryan Harris bowled Morne Morkel with two overs to go, so that's gone down to the last 10 minutes on a day five.

"I'm not a fan of four-day Test matches.

"I believe you'll get so many more draws and day five is crucial.

"One, there's the weather element. But (also) the wickets these days are probably a lot flatter than they have been in the past, so it allows teams to bat longer and to put pressure on sides … and you need that time for the pitch to deteriorate and bring spinners in more on day five as well.

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"I'm totally against it and I hope ICC aren't even considering it."

Four-day Tests are comprised of four 98-over days (as opposed to five 90-over days) and 38 of the 43 result Test matches in Australia in the past 10 years have been completed inside the 392 overs of a four-day Test.

While Lyon cherishes a fifth-day finish in Tests, only three Tests in the past decade in Australia have required more than 400 overs to achieve a result and the two Tests widely regarded as the most enthralling of 2019 – Sri Lanka’s one-wicket win over South Africa in Durban and England’s Ashes comeback at Headingley – both finished on the fourth day.

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However, as Lyon points out, the impact of wet weather and bad light can extend a Test match into a fifth day, and the longer the match progresses the more the pitch is likely to deteriorate and bring spin bowlers into the contest.

"It's a challenge," Lyon said on five-day Tests. "You challenge yourself in different ways – physically and mentally.

"It's not just a walk in the park. Five-day Test matches, they are hard work especially if the conditions aren't in your favour.

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"You want to challenge yourself. I'm all against four-day Test matches."

Former Test captains Mark Taylor and Michael Vaughan are strong advocates of four-day Tests, suggesting each match would start on a Thursday and conclude on a Sunday to provide a consistency in scheduling for fans and broadcasters.

But while CA has flagged its intention to look at the concept of four-day Test matches with a proposed maiden match with Afghanistan next year a possibility for the reduced timeslot, Roberts noted it’s still too early to be having those discussions.

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"We haven't got that far yet," he said.

"We're obviously in the middle of an exciting Test series against New Zealand that is part of the (ICC's) World Test Championship.

"Once this international season finishes, that's when we start the planning for the following season.

"And we will go into that with an open mind about how we can support the growth of cricket in Afghanistan, and the best way to help their tour to Australia contribute to Australian cricket as well.

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"I think as we explore possibilities in the next cycle from 2023 to 2031, it's very important we ask ourselves the right questions about cricket.

"We know having surveyed around 8,000 Australian fans a couple of years ago, the two main things they wanted from us were an expanded BBL and more innovation in Test cricket in the form of four-day Tests and day-night Tests.

"It's been great to have a couple of day-night Tests this year, and we've got to look really seriously at the future of four-day Test cricket.

"And given the average length of Test matches are less than four days, then it's something to consider really seriously in the next eight-year cycle from 2023."

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Test skipper Tim Paine and vice-captain Travis Head support five-day Tests and while Lyon's teammates are in the same boat as their veteran off-spinner, Australia coach Justin Langer says he would consider four-day Tests if it ensures the future of Test cricket.

"My preference – I’m a traditionalist and anyone who knows me, I don’t like to change too much – so I probably prefer five-day Test matches," Langer said today in Sydney.

"But again, like with wickets and like with schedules, if four-day Test matches keeps Test cricket alive and well then it worth looking at.

"But I love five days only because I’m boring and don’t like to change much."

Domain Test Series v New Zealand

Australia squad: David Warner, Joe Burns, Marnus Labuschagne, Steve Smith, Matthew Wade, Travis Head, Tim Paine (c, wk), Pat Cummins, Mitch Starc, Nathan Lyon, James Pattinson, Michael Neser, Mitchell Swepson

New Zealand: Todd Astle, Tom Blundell, Trent Boult, Colin de Grandhomme, Matt Henry, Kyle Jamieson, Tom Latham, Henry Nicholls, Jeet Raval, Mitchell Santner, Tim Southee, Ross Taylor, BJ Watling, Neil Wagner, Kane Williamson (c)

First Test: Australia won by 296 runs

Second Test: Australia won by 247 runs

Third Test: January 3-7, SCG (Seven, Fox & Kayo)