The circumstances surrounding Walker and Gray's situation remains unclear. Souths released a statement on Tuesday morning, saying they had both undergone off-season surgery. There is no suggestion of wrongdoing at this stage. In serious condition: Dylan Walker was rushed to hospital on Tuesday morning. Credit:Janie Barrett Despite this, their story brings a wider issue into sharp focus. Rugby league has a drug problem. It is not cocaine, despite the charges that still hang over Gold Coast Titans players. It's not ecstasy or crystal meth. It stopped being about alcohol years ago. The problem is prescription drugs. Stillies, Oxies, Benzos … take your pick.

That's not being dramatic. It's being realistic, because those who deal with the issue on a daily basis are the ones who tell you. On Tuesday, I spoke at length to a player who has been grappling with addiction to prescriptions. Of course, his anonymity needs to be protected. It's a day-to-day battle. You soon learn, though, that you could be talking to any number of young footballers across the NRL when he tells you this: "It's a massive issue for the game. All my mates have done it, and I would say one in two players have used some sort of painkiller. I became so addicted to them. The NRL needs to do something about this." In some respects, it is. Last season, the NRL announced it would test for a range of prescription drugs - including Valium, Serepax, Mogadon and Rohypnol - amid widespread rumours of their use at the World Cup the previous year.

The tests were conducted for data-gathering purposes only – not to punish players – to determine the extent of the problem before determining if further action or sanctions were needed to stop their use. If a positive test comes back, a confidential meeting between the NRL, the club doctor and the NRL's chief medical officer is established to determine why the player is taking the drug and whether he needs counselling or rehabilitation. This column understands the number of positive results from last season were so small the NRL decided to extend the testing to increase the sample size. It needs to press on because anecdotally the problem seems to have reached epidemic proportions. Last year, Warriors doctor John Mayhew – who was the long-time doctor of the All Blacks – described their use in the NRL as "widespread". Channel Nine and Fairfax columnist Danny Weidler broke the story about Walker and Gray on Tuesday, revealing Walker's sister had said her brother had taken "oxycodone and Tramadol".

These are serious substances. According to those who have used it, oxycodone has a similar effect to morphine. Colloquially, it is known as "hillbilly heroin". Tramadol is said to be the opiate of choice among league players at the moment. Drugs like Xanax fall into the category of benzodiazepines – "benzos", as the players call it – and if you take enough of them you can hallucinate, seeing objects and people who aren't there. "They are all from different families," explains one player. "But they have the same effect. And they all can ruin your life." If you're a professional footballer, you must grapple with many dynamics throughout your career, but the toughest one is constant pain.

Some are introduced to painkillers and sleepers through their club, some through other players. They all have different side-effects, especially when mixed with alcohol, but all have the same desired result: they change the channel when the rigors of playing a brutal contact sport are done for the week. If the player is sidelined with injury, especially for a long time, he might want to change the channel more often. He might get some of them from the club doctor, and then his family doctor, and then the black market via the internet. He is not alone, too, because more players are turning to them. Whatever education is being delivered in the name of player welfare, it doesn't seem to be enough.

It is easy to cast judgment and wonder why a player would do anything to jeopardise his sporting career with such destructive substances. But young footballers are more vulnerable than most as they strike to make the next tackle, the next play, the next game, the next contract. "Prescription drugs changed my life," says our addicted player. "I didn't know how bad it got until it was too late."