DAVIE, Fla. — Ricky Williams is signed up for two more seasons in the NFL. The Miami Dolphins are hoping he plays out his contract this time.

The Dolphins signed Williams to a one-year contract extension through the 2009-10 season today, putting their faith in the controversial running back even though he's bailed on them in the past.

Speaking publicly for the first time in months, Dolphins general manager Jeff Ireland said the team wanted to extend the 31-year-old so he didn't become a free agent after this season.

"I wasn't here in the past so I don't really know if he had a lack of dedication in the past," Ireland said. "I mean, I know what I read and I know what circulates in NFL circles.

"But when we sat down coming here, we said, 'We're going to give this guy every benefit of the doubt. And he's got to show us that he is dedicated.' And he's done everything that we've asked him to do. And we feel very good about our decision to extend him."

Williams won the NFL's rushing title in 2002 before flunking the league's substance abuse test five times, announcing an early retirement and torpedoing the Dolphins as they've missed the playoffs a franchise-record six straight seasons.

But his talent is why now four Miami coaching staffs have put their faith — and the team's future — on his legs. Williams has been perhaps the best player on the field during training camp, and the team has centered its offense around him in the preseason.

The Dolphins, coming off a 1-15 season, are hoping that Williams can return to his star form — and fulfill his contract.

"You guys see it out there, we see it out there," Ireland said. "He's done an excellent job in the weight room, the meeting room, he's come out there and he's jumped out at us on tape. He looks good in the preseason. So everything we've seen since we got here ... he's done everything we've asked him to do."

For now, Williams is showing the kind of effort that once led the NFL in rushing and won him the Heisman Trophy in college at Texas.

He didn't miss a voluntary practice in Miami's strict offseason workout program under the new Bill Parcells-led regime. And he has bulked up to about 230 pounds, the weight he played at in his prime.

Williams has said this season is partly about changing his legacy.

"The way I left made it difficult," Williams said during training camp. "To come back and clear my name is important to me."

A cell phone message seeking comment from Williams' agent, Leigh Steinberg, was not immediately returned.

Williams' comeback in 2007 lasted less than one half. He gained only 15 yards on six carries before he fumbled, was stepped on and tore his chest muscle against Pittsburgh.

This year, Williams is teamed with Ronnie Brown, who was on pace for a career season in 2007 before he tore a ligament in his right knee. Both running backs' contracts expire at the end of the 2009-10 season.

Ireland said the Dolphins wanted to make sure Williams remained signed with Brown.

"He's a player that's shown he can play," Ireland said. "He's shown us that he can play. So we didn't want him to make the free-agent market."

Williams was the only major roster move on a slow day for the new regime of Ireland, Parcells and coach Tony Sparano.

The team claimed New Orleans center Andy Alleman, New York Jets tackle Nate Garner and New York Giants receiver Brandon London off waivers. The team waived receiver Anthony Armstrong, offensive lineman Trey Darilek and linebacker Rob Ninkovich to clear space on the 53-man roster.