If you're worried, put yeast in. Use either dry yeast (rehydrated) or a starter that's at high krauesen. You won't need as much as for a full fermentation, obviously, but the yeast will be limited by how much priming sugar you put in. The rest will drop out when you chill the beer.
This is probably the third time I've seen this asked in the last couple of days. Was there a news story about flat beer this weekend or something?
http://www.homebrewtalk.com/f35/should-i-add-yeast-bottling-bucket-301098/