Dunne had remarked on Domenech's domestic unpopularity - in response to an earlier comment from the France coach himself - but Sagna saw that as unnecessary.
He said: "They're trying to attack the coach, they're trying to attack us. But the game will be played on the pitch. We'll try to give our response on the pitch."
Sagna was asked in turn what he thought of the Republic of Ireland coach, Giovanni Trapattoni, and about the 70-year-old Italian's 35 years in management.
"I don't know the man," Sagna said. "I don't know what he's done."