User blog comment:Xilinoc/Ch. 586 - The Headless Star 5/@comment-5693502-20140625095957/@comment-6657474-20140626035124

I'm thinking that it' a good bet the Arrancar are coming in right behind Orihime and Chad, since only Hollows, Arrancar and a handful of Shimigami have demonstrated the ability to open a Garganta. I don't believe it Chad or Orihime could do so on their own.