I've been a bit of a Walker defender because of his track record last year (and before) as well as the reality of both his contract and the fact your average #5-6 starter really isn't any better (this is nothing we didn't see from Bailey Falter last year or Allard this year). He can be DFAed but then he wouldn't have to accept an assignment to the minors. Which, no great loss, but the Phillies probably aren't ready to eat the $ or give up on him completely.
Good chance that blister is acting up or something else is sore in a few days though.
The rotation depth is probably still Top 10 in MLB. Most teams are hurting more 1-4, and their 5/6 guys aren't actually better. With the Phillies it's unfortunate that Turnbull didn't work out (and yes, got a raw deal initiallly) and Allard was kind of a bust (he was ok once he got to MLB for a bit but his overall season in the minors was disappointing) and Abel wasn't an option. Plus Painter still wasn't of course.
Nick Nelson's still ready! (just not on the 40).