Arsenal have released a statement revealing that they will 'remind players of their responsibilities' after several of them were videoed appearing to inhale laughing gas.
Ozil is seen falling semi-conscious as he inhales from the balloon, while the same can be said for Lacazette, who is videoed putting his head back on the sofa.
Summer arrival Guendouzi, meanwhile, appears to lose consciousness after taking on the gas, which has been linked to heart problems.
"The players will be spoken to about this and reminded of their responsibilities as representatives of the club," read a statement on Arsenal's official website.
The Gunners lost their first two matches of the 2018-19 Premier League campaign but are unbeaten since.