It is often taken for granted that racing drivers can do things like that, and after all, it's only a couple of years since Alex Albon performed a similar feat, returning in Singapore after missing the Italian Grand Prix following an appendix removal.
Albon, however, had two free weekends between races, so what Sainz is doing this weekend should not be underestimated.
Melbourne on Thursday was the first opportunity for the Spaniard to fully explain how his Jeddah weekend unfolded.
He didn't feel well on Wednesday, heading back to his hotel early and missing media activities. And yet on Thursday he somehow managed to complete 50 laps across the two practice sessions, taking seventh place in FP2.
"At the time it was honestly very difficult to know it was appendicitis," he explained. "What I know is on Wednesday I started to feel really bad in the paddock and I got the typical symptoms of food poisoning. I don't think I need to go into details of what that is!
"I got a very high fever also. And I spent Thursday also with those symptoms, but obviously with medication. When I was jumping in the car, I was feeling a lot better, because I was getting the medication.
"But then after those two sessions, I realised I cannot keep going like this for the whole weekend. So if I'm not improving, I'll go to the hospital.
Source: Autosport