England were rocked this weekend by a third alcohol-related incident in three months after England Lions batsman Ben Duckett was suspended from a two-day tour match for pouring a drink on the head of senior England player James Anderson following a heated argument.
The Duckett incident follows Ben Stokes' involvement in a brawl outside a Bristol nightclub in September and Jonny Bairstow's headbutt greeting for Australia Test opener Cameron Bancroft in Perth in late October.
England coach Trevor Bayliss described Duckett's incident as "trivial" but "not acceptable", and Lehmann said he did not see the funny side of his rivals self-destructing.
"I've been through all that, so no, I don't have a chuckle at that," Lehmann told reporters on Sunday.
"You have those situations at various stages throughout your career. It's not funny," he added.
"It's a case of actually making sure you're trying the best you can to get your side prepared. For me, I don't have a chuckle at any of that."
Lehmann said he has complete faith in his players.
"I trust them, obviously," he said. "They've just had a couple of days off, so they're all in today, and I'm sure they'll do well."
Bayliss said Duckett has been suspended by team management while a disciplinary investigation led by Lions coach Andy Flower takes place.
"Andy will look after his player and if anything needs to be said or done with the first team, we'll handle that," Bayliss told reporters on Saturday.
Bayliss agreed when asked if he was "fed up" about having to address off-field matters.
"Very much so. I'm here to coach the team and I end up spending most of the time trying to explain behaviour that the boys have been warned about," he said.
Australia can regain the Ashes urn with victory in the third Test starting on Thursday in Perth following big wins in Brisbane and Adelaide.
"For us we can't worry about what's going on outside with England," Lehmann said. "They're still a good cricket side and have some dangerous players."
"For us, we have got to be really switched on come day one in Perth."
Lehmann said he will assess the WACA pitch before deciding whether he needs all-rounder Mitch Marsh as a fourth paceman.
If Marsh is selected, it could be at the expense of struggling batsman Peter Handscomb.
First Published: December 10, 2017, 3:40 PM IST