I think he's working at getting better. I suspect Linn WANTS him out sooner. As for "Walk on his own ten feet?": Mary, you smokin' dryer sheets again? As far as I know, he's only ever had the two.
Seriously, when I had knee surgery, I asked when I could get out of the hospital. My doc said "Next week, probably Tuesday." I said I was hoping to be out before the weekend. He laughed and said I could leave on Friday, if I could bend my knee (operated on the day before, Tuesday) 90°. He seemed pretty sure it was an impossibility. I got out early.
It's good if they've told him what they need him to be able to do. From my visit, I think he's putting effort into the rehab, HAS made great progress and will continue to do so.