The West Coast Eagles say the drug possession charge to be dropped against Ben Cousins won't change their decision to sack the former club captain.

West Coast released a statement this afternoon after Western Australian Police notified Cousins' lawyer that they will formally withdraw a possession of a narcotic charge in Perth Magistrates' Court on Monday morning.

"This does not change the club position or the decision made on Wednesday to terminate Ben's contract because of repeated and serious breaches to his agreement with the club," the Eagles' statement said.

"The club wishes Ben well as he continues with his rehabilitation program."

Cousins's lawyer Shane Brennan told The Age Cousins was "delighted" to hear the possession charge was being dropped.

"I can tell you that I immediately informed Mr Cousins and he was understandably delighted," Mr Brennan said.

"The goal posts have moved a little, to put a nice metaphor in place."

Meanwhile, prescription drugs including diazepam, oxycontin and Viagra were found in the car that Cousins was driving when he was arrested, West Australian police said today.

WA Assistant Commissioner for Special Crimes, Wayne Gregson, said police had dropped the one drug possession charge against Cousins on advice from the Director of Public Prosecutions (DPP).

Mr Gregson said a diazepam, or Valium, pill was found on Cousins, but the DPP said that it was only a prohibited drug in a liquid, injectable form.

However he said several other drugs were also found in the car, in which there were also two passengers.

"The following drugs were seized from the vehicle: oxycontin, which is a prohibited drug, diazepam, Viagra ... and a $20 note which preliminary indications and analysis show traces of MDMA, which is ecstasy and cocaine," Mr Gregson said.

Cousins now faces one charge of refusing a test for narcotics whilst driving.

"The police have been making all sorts of noises about other things (charges) but I haven't seen anything or heard anything," Mr Brennan said.

"The next step is, that all remains is that Ben's the first person charged under a legislation that's only a few days old.

"And that will go to trial in the fullness of time next year," he said.

Cousins has never tested positive for illicit drugs.

However, in March this year, he underwent several weeks of drug rehabilitation in the United States, returning to Perth in April after agreeing to a zero tolerance clause to testing positive to banned substances.

He also agreed not to fall foul of the law.

Cousins appeared in the Perth Magistrate's Court yesterday where the matter was adjourned for three months so that he could return to rehabilitation in the US.

Mr Brennan said Cousins still planned to defend the failure to take the blood test charge.

The lawyer would not comment on how this may affect Cousins' application for a visa to the United States.