But Williams denied that the drug issue was the only reason he decided to retire, saying instead it was just one of a hundred reasons.
I didn't quit football because I failed a drug test," he said. "I failed a drug test because I was ready to quit football."
In other Williams-related developments:
-- You can add Kansas City Chiefs backup Larry Johnson to the list of potiential prospects to fill Williams' void.
Coach Dave Wannstedt mentioned his name, although Chiefs coach Dick Vermeil said he hadn't heard from the Dolphins.
Johnson was Kansas City's first-round pick in 2003, but he carried the ball only 20 times as a backup to Priest Holmes as a rookie.
Other names that have been mentioned include Najeh Davenport of Green Bay, Onterrio Smith of Minnesota, Anthony Thomas of Chicago, as well as "street" free agents Stacey Mack, Terry Kirby, James Allen, Robert Edwards, James Stewart and Dorsey Levens.
-- A lot of fans are angry about Williams' sudden retirement, and that has led to the unveiling of an anti-Ricky website called "screwricky.com.
Among other things, the website praises center Seth McKinney, who has been the only Dolphins player to open criticize Williams for leaving the team so close to the start of training camp.