Liverpool forward Raheem Sterling's apparent inhaling of laughing gas will be "a minor blip" in a "fantastic career", says a players' union chief.
The 20-year-old appears to inhale nitrous oxide in a video published on The Sun website.
Sterling will be spoken to about his lifestyle by manager Brendan Rodgers.
But Bobby Barnes, deputy chief executive of the Professional Footballers' Association, said: "He's made a mistake and people are human."
Liverpool are not expected to open a formal disciplinary investigation into the footage.
Barnes added: "Nobody would condone the use of these types of substances, whether legal or otherwise, as footballers are seen as role models.
"But many of us look back at things we did in our teens and early 20s and wish we hadn't done them."
"I am sure this will be a minor blip on his path to a fantastic career."
Sterling, who scored in Liverpool's 2-0 win over Newcastle at Anfield on Monday, also hit the headlines for the wrong reasons at the weekend when the Sunday Mirror published pictures of the player allegedly smoking a shisha-pipe.
John Bramhall, fellow deputy chief executive at the PFA, says players are educated from a young age about how to lead their lives.
"Every club has its own lifestyle programmes, offered from the age of 16 onwards - and sometimes earlier depending on a club's academy system - where they tell young lads exactly what is expected of them," said Bramhall.
"The scrutiny from the media has really increased, but I think players are becoming more aware of it and how they must conduct themselves.
|What is nitrous oxide?|
|Used in surgery and dentistry for its anaesthetic effects, nitrous oxide is also a popular legal high as it can make people feel relaxed, euphoric and giggly|
|A Home Office campaign last year on the risks of legal highs showed it was the second most popular drug among young adults after cannabis|
"Raheem's is a one-off case, I am sure Liverpool will look into it and if Raheem wants guidance, the club will be able to provide it because they have a good programme in place."
Sterling's actions have also been played down by a professor in substance use at Liverpool John Moores University.
"I don't think the club should be particularly worried," Professor Harry Sumnall told BBC Merseyside.
"Smoking and alcohol have a much bigger impact on sporting performance and are issues which affect the whole of society.
"The numbers using legal highs such as laughing gas and the harms associated with them are relatively small."
Former professional footballer Drewe Broughton is a sports movement specialist working with Premier League players. He says he has seen an increased use of the drug among sportsmen.
Speaking to Radio 5 live he said: "There is a need to take the valve off the pressure. It used to be beer and then there was the casino culture. The players have to be so careful now, everything is put online and that is the big change.
"Some of the players I work with had to come back early from their summer holidays because they felt simple shots of them having a beer would be on social media. "