Sir Alex Ferguson has confirmed that some Manchester United players take sleeping pills but that he leaves such matters to the team doctor.
"I don't know which ones," Ferguson said Friday during a news conference. "There are all different types and some very mild ones."
Ferguson clearly doesn't believe it is an issue, judging by the jovial way he responded to a further query about whether his players take caffeine tablets.
"I don't think so," he said. "It's me that's needing them."
But Ferguson may have good reason to worry. According to the results of a five-year study released this year, people who take prescription sleeping pills have a significantly elevated death risk.
"We are not certain. But it looks like sleeping pills could be as risky as smoking cigarettes," study leader Daniel F. Kripke, emeritus professor of psychiatry at the University of California, San Diego, told WebMD in February.
"It looks much more dangerous to take these pills than to treat insomnia another way."
Heavy sleeping-pill users had a 5.3-fold higher death risk and a 35 percent-higher risk of cancer, WebMD reported, citing the study. Those who were prescribed 18 or fewer sleeping pills a year had a 3.6-fold higher death risk, according to the report.
The issue of what soccer players take to get to sleep has become a discussion point after Glen Johnson revealed some players had taken caffeine-based energy pills on Tuesday ahead of England's World Cup qualifier with Poland in Warsaw, a 1-1 draw.
Another England player admitted some then took sleeping pills to counter-attack the effect and allow them to get to sleep following the postponement.
Both Phil Neville and Rio Ferdinand went on Twitter to confirm it was nothing new and that neither sleeping pills nor caffeine tablets, which it has also been suggested were taken by Roy Hodgson's men, had an adverse effect on player performance.
"I wish I had taken a sleeping tablet before this press conference," Ferguson said. "It would have made it a bit easier."
Information from the Press Association was used in this report.