But Dolphins coach Tony Sparano said the workout is merely an evaluation of Carter, an Arena Football League quarterback who started for the Cowboys and New York Jets before poor play and drug-related arrests ended his NFL career.
"We're just going to keep turning over, flipping over stones and bringing in a lot of people," Sparano said. "And it probably won't change for two to three years. Quincy is here and we will have a workout with Quincy."
Sparano said he's been pleased with all three quarterbacks currently on the roster -- Josh McCown, John Beck and rookie Chad Henne -- and Carter's workout is not a sign the team wants to move away from them.
"I have been pleased with the quarterbacks, and I think the competition is really good," Sparano said. "It just means we have to make sure we're doing our due diligence on what's available."
Carter was dismissed by the Cowboys in 2004 -- a team coached by Parcells, now vice president of football operations for Miami. Carter's understanding of the Dolphins' offense would seem to make him a good fit in Miami, which has struggled to get consistent quarterback play in training camp.
The Dolphins are also considering signing former Dallas receiver Terry Glenn.
Glenn was released by the Cowboys last week because he would not accept a salary cut after trying to return from two knee operations last year. His only appearance for Dallas came in a playoff loss to the New York Giants, when he caught two passes for 30 yards.
"I'm sure it makes sense that you'd be interested because we know the guy," Sparano said. "We know him. We've coached him. Bill's coached him for years, I've had him for four or five years down there in Dallas."
Since Parcells joined the Dolphins in December, they have repeatedly lured coaches, players and even general manager Jeff Ireland away from the Cowboys.
Carter's best season was in 2003 when he led the Cowboys to a 10-6 record and a playoff berth. He completed 292-of-505 passes for 3,302 yards and 17 touchdowns with 21 interceptions and rushed for 257 yards and two touchdowns.
"Quincy was athletic. He can move, and he can make some plays that way," Sparano said. "He was an intelligent guy and a pretty good motivator."