Key said he previously looked into reports that white-ball captain Harry Brook and batter Jacob Bethell were drinking the night before a match on the limited-overs tour of New Zealand that preceded the Ashes.
A clip of Brook and Bethell was shared on social media, reportedly taken in Wellington the night before the third one-day international on 1 November.
“I didn’t feel like that was worthy of formal warnings, but it was probably worthy of informal ones,” said Key.
“There wasn’t any formal action. We’ve had four years where we’ve had none of these issues really, with any of the players, and there’s a whole process that we put in place for stuff like that – for what you do if they’re out of line.
“That was a bit of a wake-up call for what they’re going into. I don’t mind players having a glass of wine over dinner. Anything more than that, I think is ridiculous.”
Despite the questions over the behaviour of some players in Noosa, Key defended their right to take the break from the Ashes.
Brook, Bethell, Ben Duckett, Jofra Archer and others could spend almost six months away from home following the tours of New Zealand, Australia, and the T20 World Cup in India and Sri Lanka in the new year.
“Harry Brook is going to only be at home for six days this entire winter,” said Key.
“We have to create a time where these players can get away from cricket because they’re not going to do it by being at home.
“We live in an age as well where it’s impossible to avoid cricket. I sit there on my phone and every Instagram thing comes up. I know that players say they shouldn’t look at it, but they do.
“You can’t escape cricket, especially on an Ashes series and the scrutiny. Getting away and being able to just forget about that and live like a normal person is really important.”