Miami Dolphins running back Ricky Williams has violated the NFL's substance abuse policy for a fourth time and is facing a one-year suspension from the league, Denver television station KDVR reported on Sunday.
The Miami Herald, citing two sources of its own, confirmed the station's report that Williams has violated the policy, although neither source would say whether Williams had failed a drug test or if he had missed a required test, which also is a violation.
An NFL spokesman told ESPN that the NFL had no comment on the report.
Williams has tested positive for marijuana three times and served a four-game suspension when he returned to the NFL last season following a one-year retirement.
Dolphins coach Nick Saban told ESPN he was not aware that Williams had tested positive and he was not allowed to comment, citing the confidential nature of the league's substance-abuse policy.
Dolphins spokesman Harvey Greene declined to comment when reached by the Herald on Sunday night.
"Because of the confidential nature of the league's substance abuse policy, we can't comment on any aspect of that program," Greene told the newspaper.
Williams was also fined the equivalent of four weeks' salary after his second and third violations of the NFL policy, in December 2003 and the 2004 offseason.
His mother, Sandy Williams, told the Palm Beach Post she would be "shocked" if her son would use marijuana again and strongly doubts that is the case.
Sandy Williams told the newspaper her son is currently in India and that they had not spoken of late. She speculated that he could have tested positive for a legal supplement he is taking in connection with his yoga studies.
"I'll bet my life he's not smoking marijuana," she told the Post on Sunday. "He's so particular about what he puts in his body now. I would just be shocked. I just don't believe he's smoking weed."
"I'm thinking maybe it was one of his [legal] supplements for his yoga school. I really just don't believe he's smoking weed."
Williams abruptly retired from the NFL in July 2004 and the Dolphins fell apart, losing their first six games and finishing 4-12 -- their worst season since the 1960s.
At the time of his return, Williams was ordered to pay the Dolphins $8.6 million for breaching his contract, although there has been no financial resolution between him and the team. He was scheduled to be paid the league minimum of $540,000 last season, but was docked four games' pay due to his league-mandated suspension and was fined another four games in pay, reducing his take to $285,882.
Williams' base salaries for the two coming seasons are $545,000 and $670,000, the minimum for a player (he entered the league in 1999) of his NFL tenure.
Motivated partly by the need for a paycheck, he accepted Saban's offer to return for the 2005 season. When he reported at the start of training camp, Williams publicly apologized for the impact caused by his retirement and teammates unanimously embraced his return.
The Dolphins finished the 2005 season 9-7, winning their last six games. Williams gained 743 yards and scored six touchdowns.
Williams won the Heisman Trophy, the Maxwell Award, the Walter Camp Award and the Doak Walker Award following his senior season at Texas, in 1998. The New Orleans Saints traded away all their picks in the 1999 NFL draft in order to get him.
In six seasons with New Orleans and Miami, Williams has 7,097 yards on 1,757 carries -- four yards per carry -- and 47 rushing touchdowns. His best season was in 2002 with Miami, when he gained 1,853 yards in 383 carries and ran for 16 TDs.
Information from The Associated Press was used in this report.