They need to sweep?  No chance.  After this series, Your Js still have 120 games to play, roughly 3/4 of the season.  

You don't want to lose to Atl, pretty decrepit, but it's not like Your Js are world beaters yet, the last 2 weeks or so notwithstanding.  Your Js are the better, but not by much, at least going by the standings and stats.

A split at minimum, yes, taking 3 outa 4 works, a sweep great, but not necessary.