Buehler just threw his first game back last week. I think he'd probably be fine by the playoffs. Kershaw, Lynn, Miller, Buehler or Pepiot/Sheehan who held us to 1 run isnt the worst rotation to roll out.
Buehler is essentially in Spring Training at this point. For reference, Wright has already made a couple rehab starts and is expected to make 2-3 more rehab starts. His timetable for return looks like it will be 9/20 at the absolute earliest, but more likely to be 9/26, giving him 2 starts before the playoffs start. And he isn't coming back from a major surgery like Buehler.