Thomas Frank said Tottenham are "dealing" with Yves Bissouma's behaviour after the Mali midfielder allegedly inhaled nitrous oxide for a second time in as many seasons.
Bissouma has yet to feature under Tottenham manager Frank since being dropped before the UEFA Super Cup clash with Paris Saint-Germain in August for repeated lateness.
The 29-year-old underwent ankle surgery in October but his hopes of being selected by Frank suffered a setback after a report in Britain's Sun newspaper last weekend showed footage of Bissouma allegedly inhaling nitrous oxide – widely known as 'laughing gas'.
If confirmed, this would be the second time Bissouma has been involved in such a scenario after he was handed a one-match ban at the start of the 2024/25 campaign for a "severe lack of judgment" when filmed inhaling nitrous oxide.
Under English law, nitrous oxide was made a Class C drug in 2023 and possession of 'laughing gas' for recreational use is a criminal offence.
-- NIGERIA ONLY --
Frank, speaking ahead of Tuesday's Champions League tie at home to Slavia Prague, said: "It's an internal matter that we are dealing with at the moment and when we have dealt with that, then I will comment on it."
Bissouma was already out of the Slavia tie and Frank added that Tottenham left-back Destiny Udogie will be sidelined until the new year.
"Destiny picked up a hamstring injury in the end of the Newcastle game (a 2-2 draw on December 2), so he's out until January unfortunately," Frank said.
But France forward Randal Kolo Muani, on loan from Paris Saint-Germain, trained Monday after limping off during Saturday's 2-0 defeat of Brentford.
Victory over Brentford ended Tottenham's wait of nearly four months for a Premier League win at home and eased a little of the pressure on Frank after a disappointing run.
"It's always good to build and get the momentum to get more consistent and good performances," said Frank. "We really try to build on that."
Frank declined to comment on 16th-placed Tottenham's chances of finishing in the top eight of the Champions League which offers automatic qualification for the last 16.
"I am more about this next game ahead of us," he said.