The 2002 league rushing champion, who has played in only 12 games since the start of the 2004 season, was in the Canadian Football League last season and applied for reinstatement Oct. 1.

He was suspended last year after violating the league's drug policy for the fourth time and tested positive again for marijuana in April, delaying his return through the first half of this season.

Williams remains under contract with the Dolphins. But first-year coach Cam Cameron, whose team is 0-9, has given no indication he wants Williams.

The Dolphins had no immediate comment on Williams' reinstatement.

The league said Williams is eligible to attend team meetings and practice immediately, but will not be able to play in a game until Miami plays at Pittsburgh on Monday night, Nov. 26. The team will have a roster exemption for up to two weeks if and when he starts practicing.

"Ricky worked extremely hard to meet the requirements for reinstatement," said his attorney, David Cornwell. "He is grateful for commissioner Goodell's decision. Ricky is committed to making the most of the opportunity to rejoin the NFL."

Williams rushed for 3,225 yards in the 2002 and 2003 seasons after being traded to the Dolphins from New Orleans. He then retired in 2004, traveling in India and Australia before returning to the Dolphins in 2005, when he ran for 743 yards alternating with rookie Ronnie Brown.

Brown is on injured reserve, leaving the Dolphins short on running backs. But they may decide to keep Williams inactive the rest of the season and then try to trade him.

In May, when discussing Williams' most recent relapse, Cameron said it's difficult to salvage the careers of troubled players.

"The easiest predictor of future behavior is previous behavior," the coach said.

Dolphins general manager Randy Mueller is unlikely to lobby for Williams' return. It was Mueller who traded Williams to Miami when both were with the Saints.