This is great to know!
Thanks very much everybody for the response. That is what I was looking for. I think one has the tendency to go through a surgery, and you work really really hard on rehab, and for some reason you think that now everything is going to be perfect.
Well I am really happy with progress so far except for this small glitch, but I do realise that it may take a bit longer to get back to 100% with serving (I can't help it but I have to hit a nice hard first because I love getting the points on it that I do)...
I am definitely sticking with the resistance bands and even some light weights because that really helps. I agree that developing stamina is the most important thing and that the serving will probably come with that. Great to hear you have all been there and that inevitably I just need a bit of time and patience!