Announced attendance at the first two fixtures of the current Braves-Marlins series have been 12,916 Monday and 16,386 last night (that first figure must suggest that the Braves' season ticket base must either really be drying up, or hasn't been any great shakes to begin with).
By contrast, the Nats haven't been below 20k at home since 4th September 2012 (a Tuesday Cubs visit with 17,648).