Ferguson has an elbow injury that has limited him in practice all week, while Crowder is still bothered by a shoulder injury.
Both players are listed as doubtful for Sunday's game against the New England Patriots at Gillette Stadium.
They are the only two players on the Dolphins' injury report. Ricky Williams was on it last week with a thumb injury but he never appeared this week.
The Patriots, meanwhile, have players listed as out: WR Julian Edelman (forearm), DE Jarvis Green (knee), T Matt Light (knee), RB Sammy Morris (knee) and RB Fred Taylor (ankle).
The Pats also list as questionable DE Ty Warren (ankle), TE Benjamin Watson (back) and CB Jonathan Wilhite (illness), while QB Tom Brady and WR Randy Moss both are listed as probable with shoulder injuries.