Really worrying if it's a form of sciatica, i had that a few years ago. Best way of describing it is that it's like a permanent leg cramp (multiplied by 100)!, I was off work for 6 weeks til the anti inflammatories sorted it. Couldn't move off my couch because of the pain. Great that he went out onto court to talk to the crowd, as well as being a nice gesture it also means that the injury isn't as bad as it might have been. Here's hoping he doesn't lose the momentum he has worked hard to create in the past few weeks.
You never know, but I'm thinking since he's probably in better shape than any of us he will get over it sooner rather than later. (not to mention on the spot physio). I've had it too, remember thinking if I could hang upside down by my knees it would work itself out, being as it felt like something was jarred. Eventually a couple of swimming sessions seemed to make mine better.