Butler's injury sounds like a sprain. Just a little more time, and he would've played from the sound of it. Don't want to rush him back, though, since those can nag.
Kriisa with a Jones fracture is bad. Google says 3-6 weeks. Having a similar injury in the past (bone within/near a joint at a location with poor blood flow), I expect this to actually take 6-8 weeks to get Kerr back. Longer to get into proper condition and flow.
Gonna need Butler, Perry, and that PG committee to step up.
This is all speculation, of course.