Miami, Florida - Miami Dolphins running back Ricky Williams has tested positive for marijuana and will not be allowed to apply for reinstatement to the NFL until September.

Williams was suspended last year for violation of the substance abuse policy and was eligible to be reinstated this month, but the league's medical advisors that oversee Williams' personal rehabilitation program recently notified commissioner Roger Goodell of the positive test, sources said.

The doctors also recommended that Williams not be allowed to apply for reinstatement until September, sources said. The commissioner usually adheres to the advice of the medical advisors under the substance abuse policy. 

"Falling off the wagon is part of rehab," a source said. "Based on the medical evidence in Ricky's case, the doctors say it's too early to come back. He had the positive test last month. Remember, he's been diagnosed with social anxiety disorder -- that's a real disease and a good percentage of those folks self-medicate with substances like marijuana, often at the moment they are about to have a high level of social interaction." 

League spokesman Greg Aiello said the NFL would have no comment, as did Dolphins spokesman Harvey Greene. 

David Cornwell, an attorney who has represented Williams during his substance abuse cases, said he would honor the confidentiality policies in effect with another no comment.