London - World football officials have warned that Rio Ferdinand will be punished if the English Football Association lets the Manchester United star off for missing a drugs test.
The warning comes from Michel DHooge, head of Fifa's medical committee and the man in charge of their anti-doping programme.
"This is a serious case. Ferdinand certainly has to be punished," he told British media.
"Fifa is waiting to assess whether a serious sanction is forthcoming - one which fits the infringement.
"We will let the English do their work first. If everything is correct we won't have to do anything."
But the Belgian insisted he expects the FA to come down heavily on the England defender.
The World Anti-Doping Agency regulations call for a two-year ban but D'Hooge said Fifa uses their rules as a guideline.
"We are applying individual case management in these circumstances. The sanction could be less than two years or it could be more."
DHooge said Ferdinands case will be discussed during a Fifa executive board meeting in Qatar at the weekend.
Ferdinand - accompanied by lawyers from Old Trafford - was interviewed for two hours by FA compliance officer Steve Barrow on Monday.
The 33-cap England star admitted missing the drug test at Uniteds training ground on September 23 but insisted he simply forgot.
Uniteds lawyers pointed out Ferdinand had offered to undergo a test as soon as he realised his mistake and provided a negative sample two days later.
The Premiership champions are pushing for a charge of missing a drug test which would be punishable by a hefty fine and a brief suspension.
But, if Ferdinand is hit with the more serious charge of wilfully missing a drugs test, he could be liable to a ban of up to two years.
FA chiefs who axed Ferdinand from Englands final Euro 2004 qualifier against Turkey last Saturday are still deliberating over their course of action.
Ferdinand could be charged on Wednesday but United insist they will not suspend the player until the case has been dealt with by the FAs disciplinary committee. - Sapa-AFP