User blog comment:Xilinoc/Ch. 574 DEATH IN VISION/@comment-3405923-20140326153450/@comment-11051098-20140326204757

Unohana is dead and he's done talking to his Zanpakutô spirit. I imagine that he got bored and went to pick up his eyepatch and see if he could find a Sternritter to kill. He sensed Yachiru's reiatsu weakening and decided to go there to see what was going on.

He always wore the eyepatch to extend his fights. Why would he change that, especially now that he's stronger than he's ever been in the story? Although Gremmy's talk might annoy him enough to go for the kill sooner instead of later, like he did with Berenice in the first invasion. Annoying talk = kill them right away.