No laughing matter? Liverpool's Raheem Sterling caught inhaling nitrous oxide

LHe's been heralded as one of Europe's best young footballers, but it's not just the backpages that can't get enough of Raheem Sterling.

Sterling shone in Liverpool's 2-0 win over Newcastle United on Monday, but an article published by British newspaper The Sun alleges to show a video of him appearing to inhale nitrous oxide or "laughing gas" from a balloon.

The UK tabloid says it led to a dressing down from the team's manager Brendan Rodgers.

"I don't think it is something you should be doing, it's as simple as that," said a straight-faced Rodgers during his post-match press conference -- adding that he would have a word with Sterling about his off-pitch behavior.

"We want players here who are super professional and focused on their football. I know he is. He very much is focused on his football and improving as a player.

"But I will speak to him on it, and we'll move on. Young players make mistakes. As long as they learn from them, that is what is important."

In recent weeks, Sterling has been in the media spotlight for off the pitch issues as much as his performances on it.

In a recent interview with the BBC, the 20-year-old star admitted rejecting a reported multimillion dollar contract offer from Liverpool -- to the annoyance of some of the club's supporters.

The report of Sterling's alleged nitrous oxide usage is unconfirmed.

Jamaican-born Sterling has not made any public comments about the video, or what he was doing. Neither he, or his representatives have responded to CNN's calls for comment.

Sterling was heckled by some fans during a recent event to launch Liverpool's kit for the 2015-16 season.

Last weekend, a social media post which was widely reported in the British media appeared to show Sterling smoking a shisha pipe. It raised concerns over his professionalism.

No laughing matter

Nitrous oxide is a legal drug known for its anesthetic effect, used by surgeons and dentists to relax their patients.

With 7.6% of 16-24-year-olds in the UK reporting nitrous oxide use in 2013/14, it's the second most popular recreational drug -- with users feeling euphoric and relaxed and some experiencing hallucinations, according to a Home Office report.

"Inhaling nitrous oxide can be dangerous, and can lead to loss of blood pressure, fainting and even heart attack," the report says.

"Prolonged exposure to nitrous oxide may also result in bone marrow suppression and poisoning of the central nervous system with risks being exacerbated when combined with alcohol or other drugs."

Former Liverpool defender turned broadcaster Jamie Carragher said on Sky Sports: "Whether you're a Premier League footballer or you're a 20-year-old kid or whatever, you make mistakes at that age. I did and I'm sure we all do.

"It's just important he learns from it because Raheem Sterling, for how good a footballer he is, needs to be on the back pages, not on the front pages.

"But he's a young player, he made a few mistakes and hopefully in years to come he learns from them."