Ange Postecoglou has confirmed Yves Bissouma has been suspended for Tottenham's opening game of the Premier League campaign against Leicester.
Bissouma, who made 28 appearances last season, posted a video of himself inhaling nitrous oxide on social media last weekend.
The incident occurred hours after Spurs' final pre-season clash, where they lost 3-2 to Bayern Munich in the Visit Malta Cup.
The 27-year-old later issued an apology, saying: "I want to apologise for these videos. This was a severe lack of judgement.
"I understand how serious this is and the health risks involved, and I also take my responsibility as a footballer and role model very seriously.”
However, Spurs have since taken the decision to exclude the midfielder from the squad for their trip to the King Power Stadium on Monday.
"I've been in the game for a long time. When a situation like this arises, I've tried to look at them in a couple of ways," Postecoglou said in his pre-match press conference.
"First, there's a person. That's Biss and he's made a poor decision.
"There are still sanctions involved, and some of those are educational. The second part of that is he's a footballer, with responsibilities.
"He won't be available on Monday. We've suspended him for Monday's game. He needs to build that trust back with both me and the group.
"The door is open for him and hopefully we can help him realise the decisions he makes impact the group.
"[It's down to] behaviour, it's that simple. It's about making better decisions. He was very apologetic to me, the club and everyone involved, but that's just part of it."