However, Flores indicated that while Fitzpatrick will start against the Cowboys, nothing beyond that is set in stone.
"After a couple of weeks like that, we're evaluating all positions," said Flores. "We haven't made any final decisions yet."
Fitzpatrick, who set multiple NFL records in Week 2 by throwing both a touchdown and an interception for his eighth different team, was signed by the Dolphins this offseason on a two-year deal. Rosen was acquired from the Arizona Cardinals for a second-round pick in April.
Flores offered some insight into how Rosen can help his own cause as he works to capture the starting role.
"Do a good job in meetings, walk-throughs, and practice," Flores said.
The Dolphins are sporting a ludicrous minus-92 point differential through two weeks. For his part, Fitzpatrick has thrown for 274 yards, one touchdown, and four interceptions while completing 50% of his passes with a 39.9 passer rating. Rosen hasn't fared much better in limited playing time, going 8-for-21 for 102 yards and a pair of picks.