My sister just went through this a couple of months ago. If they are able to do it by going through an artery in his groin he will be back on his feet very quickly.
If they wind up having to go through the chest wall like they did her we have seen the last of him on the field this season.
This is apparently something John was aware of. He had a meeting with his doctor on Thursday to see if they could postpone the surgery until February, and then he had the episode on Saturday so they've decided to do the surgery now.