User blog comment:Roranoa Drake II/Chapter 825: Too Short, but Golden/@comment-24850639-20160502183058/@comment-25926617-20160502231730

BB has a crew of 11 right? so that would mean Luffy would have 11 which means he meant 10 besides him.... So two more members.

Oda did say that the next two members would join successivly but he could have been referring to the Grand Fleet so that may be out of the question. Tho if the last person doesn't join by Kaido going down I would be a bit disappointed because I feel like that is a huge accomplishment that should cement the crew together and anyone joining after would seem by themselves.