Miami ? Ricky Williams will sit out another season.

The NFL suspended the troubled Miami Dolphins running back for one year Tuesday after he violated the league’s substance-abuse policy for the fourth time.

Williams met April 10 with NFL counsel Jeff Pash in an attempt to have the league overturn the test. He had been participating in the offseason training program at the Dolphins’ complex, and he was there working out shortly before the league announced that his appeal had been rejected.

“I’m disappointed with the decision, but I respect it,” the 2002 NFL rushing champion said in a statement released by the team. “I’m proud of my association with the National Football League and look forward to returning to the Dolphins in 2007.”

Williams also sat out the 2004 season after retiring shortly before training camp. He returned last year to play for new Miami coach Nick Saban.

Williams’ previous positive drug tests were for marijuana, which he acknowledged using. The latest test apparently involved a substance other than marijuana and may have been related to his interest in holistic medicine.

Since his return last season, the NFL required Williams to undergo drug tests up to 10 times a month. He was in India studying yoga when news of his latest failed test surfaced in February.

Williams served a four-game suspension at the start of the 2005 season for his third violation of the drug program, then ran for 743 yards and averaged 4.4 yards a carry while sharing playing time with rookie Ronnie Brown.