Davie, FL (My Sportsbook) - The Miami Dolphins have placed running back Ronnie Brown on injured reserve because of his foot injury.

Brown had already been ruled out of Thursday's game against the Carolina Panthers because of the injury, but now the team's leading rusher will be out for the rest of the season.

He suffered the injury in this past Sunday's win over Tampa Bay, as he rolled what appeared to be his right ankle late in the third quarter. Brown was on crutches after the game.

Dolphins head coach Tony Sparano said Tuesday that the injury was more of a foot injury than an ankle issue, and that Brown would see a specialist.

In nine games this season, Brown has a team-high 648 yards on the ground with eight touchdowns.

Ricky Williams will start at running back Thursday in place of Brown. Williams has rushed for 558 yards and six TDs on 105 carries this season. Third-string RB Lex Hilliard could see an elevated role with Brown being out.

Also Wednesday, the Dolphins signed safety Nate Ness from the team's practice squad to replace Brown on the active roster.