An early estimate has Fiedler missing about a month of action, which would put Ray Lucas in the starting lineup.
Fiedler was injured when his hand hit a helmet on a 5-yard pass to Ricky Williams on the Dolphins' next-to-last drive.
Fiedler threw six more passes after the injury, completing three of them. Included were a 17-yarder to Randy McMichael, followed by a 22-yard completion to Dedric Ward that set up Mare's 53-yard field goal.
Said Coach Dave Wannstedt: "He made some big-time throws under pressure."