Professional Footballers' Association chief executive Gordon Taylor says that education and regulations around the use of drugs in football need to be improved, after a week of high-profile suspensions.
Hull's Jake Livermore was suspended by his club and the FA on Friday for testing positive for cocaine, while on Saturday Wolves goalkeeper Aaron McCarey and Sheffield United forward Jose Baxter were suspended for failing out-of-competition FA drugs tests.
Testing has become more rigorous with players now tested on average three times a season, but Taylor believes that more needs to be done.
"The education and regulations need to be enhanced, clearly," Taylor told BBC Radio 5live's Sportsweek programme. "They have probably never appreciated the seriousness of what's happened.
"We certainly can't relax now. We have to look at the education and advisory service. They probably do not appreciate the consequences, not just for them and their careers, but for their families."
Under FA rules, players who test positive on matchdays for illegal "social" drugs can face up to a two-year ban. Chelsea sacked Mark Bosnich in 2003 and Adrian Mutu in 2004 after both tested positive for cocaine, while Manchester United's Rio Ferdinand was banned for eight months after missing a random drugs test, despite not testing positive for any substance.
Hull manager Steve Bruce said after the 2-0 defeat to Tottenham this weekend, for which Livermore was suspended, that owner Assem Allam would make the decision whether to sack the 25-year-old.
"I haven't had the conversation," he said in the Daily Telegraph. "But I am sure, knowing the owner the way I that I do, he would want to do the right thing. I think that's vitally important.
"Whatever that right thing is, people have their own opinions and when I have the conversation with the club then I'll certainly have my own thoughts. But at this moment in time I think the authorities had better do their job and do the right thing, and see where it ends up."
Bruce offered no excuses for Livermore's behaviour, while suggesting that there were things that both the club and the FA could improve upon in the testing procedure.
"I'm sure there's mitigating circumstances for the reason why, I'm sure there will be a lot that comes out," he added. "Obviously society -- and I get called a dinosaur very often -- society has changed, there's no question about that. It's out there and temptation, unfortunately, becomes great. However, he's a professional footballer with the world at his feet.
"You can't fail a drugs test now and get away with it, not with the world doping authority the way it is. It is highly professional. They have been to our club 15 or 16 times. It's so high profile now the Premier League and rightly so that we're talking about a player that took a social drug, it's just ridiculous.
"They are professional footballers and there hasn't been a case for what, 10 years, and if they've been to our club 15 times then they've been to every other Premier League club 15 times and week in week out, there's nothing. It's well run, there are certain things we could probably improve on.
"Could we embark in doing it ourselves every week? That might be a way forward, but I don't think legally you would have a cat in hell's chance of doing that."