Hope that isn't too hasty. Having your appendix out is a routine/common procedure, but a fairly large one still. I had mine out when I was younger and was in hospital on a drip for 4 or 5 days after and then had to have a further two weeks off with no strenuous activity to ensure the massive stitched up opening on my stomach didn't rip apart!
I'm sure Sainz is getting much better care and medical attention than I did
Edit: just read up on it and he may well have had a laproscopic appendectomy which avoids making one large incision and has a shorter recovery time. Two weeks still seems about on the limit though.