I wouldn't be surprised if the heat from the tour didn't get to him and he needs a few weeks to get together. It's been a brutal couple of weeks on the east coast and they played outside every gig. John said it was a sweaty affair through and through.
I've heard from a couple unreliable sources that he's just not ready to tackle all the material solo yet. If you watched the Tri-Studios show, he was certainly working out a lot of kinks in the music. On the bright side it sounded like he was actually singing rather than the 'word jazz' he seems to be doing lately.