England wicketkeeper Jos Buttler says he would welcome discussions about the possibility of playing four-day Test matches.
The International Cricket Council (ICC) is reportedly considering introducing mandatory four-day Test matches, with a one-day reduction in match length likely to be discussed this month.
Any changes would come into effect from 2023, with the English and Wales Cricket Board (ECB) having stated it "cautiously" supports the mooted proposals.
Buttler would also welcome the alteration if it helps to retain and increase interest in Test cricket, though the wicketkeeper-batsman would prefer a five-day format.
"I think the administrators and broadcasters have got to look at the best way to preserve Test cricket," World Cup winner Buttler told BBC Sport's Test Match Special.
"It's the best form of the game, so how can we maintain that and keep moving the game on?
"If that's the option, moving it to four days, that has to be looked at. I like that it's five days, when you get a fantastic Test that finishes on day five with all three results possible there's nothing else really like that in cricket.
"As with everything, times change, things change, and the game has to evolve with that. Everyone has to be open to change if that’s what is needed."
Buttler is currently preparing for England's second Test against South Africa at Newlands in Cape Town, with the tourists having lost the first match by 107 runs.
The majority of England's squad suffered from illness before or during the Test, with a bug sweeping through the camp, though Buttler – who also suffered from the symptoms – is hopeful the worst has now passed.
"Pretty good, it was nice to have a full squad at training. Nice to celebrate the new year last night and come to this iconic Test venue," he added.
"Everyone's back together and all of the families. It's quite a large group out here which is nice, a special time to spend with your families and we had a really nice night.
"A few days [of the illness] seems to drain you of a lot of energy. But it's just one of those things that has gone around the team. Touch wood it's all gone.
"It certainly didn’t help us [in the first Test] but as Joe [Root] said you don’t want to hide behind that. In the game the two key moments were having South Africa 111-5 and us being 140-3 and after the first innings they ended up with a 100-run lead so that’s really where the game was won and lost, we're very aware of that."