I think we will see Buxton on the IL before we see him in CF.
Hindsight being 20/20 and all, I think the team should have placed him on the IL after he hurt the knee against Boston last season, he may have damaged the knee more by continuing to play on it, as witnessed by the fact he didn't have surgery until November despite being shut down at the end of August. Sano (bad example, I know) returned in about 6 weeks from his surgery, if Buxton would have had the surgery immediately after the injury, he is back around mid- June/early July.
The team also should have been a little more vocal about him skipping the All-Star game and getting that injection/treatment instead. Personal accolades are fine, but this is a team sport and his team needed him healthy (as much so as possible anyway) for the 2nd half.
I am as big a fan/supporter of Buxton as anybody, but I don't think we'll see him CF any time soon.