According to ESPN.com, the Dolphins' leading rusher has been placed on injured reserve and will be out for the rest of the season. Brown hurt his foot on Sunday in a win over the Buccaneers and was sent to see a specialist for further evaluation on Tuesday, according to head coach Tony Sparano.
Backup Ricky Williams will replace Brown as the starter on Thursday and will serve as the primary back if the Dolphins choose to run the Wildcat.
The good news is that Williams is currently averaging a career-best 5.3 yards per carry. The bad news is he'll carry the added pressure of making up for the loss of Brown's 648 yards and eight touchdowns.
Sparano told ESPN.com he isn't worried.
"[Williams] takes tremendous care of himself," he said on Tuesday. "This guy has worked like crazy for the year and a half that we've been here. Watching him work the way he works, you wouldn't think he's  years old."