DAVIE, Fla. -- Safety Sammy Knight signed a two-year contract Tuesday with the Miami Dolphins, then began to contemplate trying to tackle former New Orleans teammate Ricky Williams each day in practice.

"Ricky runs 50 to 70 yards every play," Knight said with a smile. "If I'm chasing him, I'll probably be playing cornerback by the time I'm done, I'll lose so much weight."

That's not what the Dolphins have in mind. They want the 6-foot, 215-pound Knight battling strong safety Arturo Freeman for a starting job and the chance to play with Pro Bowl free safety Brock Marion. Miami also has two Pro Bowl cornerbacks -- Sam Madison and Patrick Surtain.

Knight agreed to a two-year, $2.38 million contract that included a $300,000 signing bonus, ESPN.com's John Clayton reports. Knight joins a Dolphins defense that has eight current or former Pro Bowlers.

A Pro Bowl safety in 2001, Knight opted out of a deal that would have paid him $1.5 million this year with the Saints, who said they wanted more speed at safety. But the Dolphins like Knight's toughness and playmaking ability.

"You can coach guys sometimes until you're blue in the face, and they can be in the right spot, but they never seem to make the play," coach Dave Wannstedt said. "That's God-given, and Sammy is one of those guys over his career who has found a way to make the plays."

Knight made 28 interceptions in six seasons as a starter for the Saints. Freeman has one interception in three seasons.

"A lot of times people make the game too complicated," Knight said. "When the ball is in the air, you have to say it's mine and go after it. I just try to make the game simple."

As for Knight's speed, Dolphins personnel chief Rick Spielman decided it was sufficient after watching film of eight Saints games.

"You never saw him get beat," Spielman said. "A lot of that has to do with guys who have a natural instinct, and maybe they have a speed limitation but know how much cushion they have to give and when to break. He has a knack for that."

The Dolphins' defense has acquired three other significant veterans this offseason -- linebacker Junior Seau, tackle Jeff Zgonina and cornerback Terrell Buckley. In addition, top draft choice Eddie Moore may challenge incumbent Morlon Greenwood for a starting spot at outside linebacker.

Knight canceled a visit Monday to Green Bay and instead flew to Miami to seal his deal.

"The deciding factor was all the things they were doing down here, the moves they were making to win," Knight said. "I thought something special was going on down here, and I wanted to be a part of that."

Information from The Associated Press was used in this report.