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.
"I didn't improve, and the morning of the Friday, which was qualifying day, I went to the hospital and I got diagnosed with appendicitis, which was not easy to diagnose, because my analysis and the test that they were doing, it was not clear.
"So I didn't have the typical symptoms of appendicitis. But they were pretty convinced it could be, and I got the surgery done.
"It was a great job from the doctors because as soon as I got it removed, I felt back to normal, back to better, obviously with surgery, and I could start focusing on recovering."
Sainz flew back to Europe on the Sunday after the race to begin his recuperation, the sole target being to get on the plane to Australia and be ready to drive the car in FP1.
He was not able to do his regular training, and it was also decided not to travel to Maranello for sim running in order to focus all his energies on his recovery. The recuperation wasn't as easy as expected.
"Every day I'm feeling obviously a lot better," he said. "Now, every 24 hours that I do, I do a lot of progress. It's true that the first week was tough, a lot of time in bed and recovering. And that's when you see things a bit darker.
"But then in the second week, the recovery speeds up a lot. And I started to feel a lot better. So yeah, I'm confident that I can jump in the car tomorrow and do well.
"Obviously, I put together a very strong recovery plan since day one that I landed back home to be ready for this race."
He was helped by the fact that an appendix removal, while not exactly pleasant, is not quite as dramatic an operation as it was just a few years ago.
"First of all it's possible thanks to the advances that the medicine has done in the last 20-30 years," Sainz explained. "When my dad had the operation, and maybe some of you guys had it 30 years ago, they cut you open.
"Nowadays, with laparoscopy, they do three very little holes, that speed up the recovery. It's twice as fast or three times as fast as it used to be.
"So thanks to that is why even the doctors after the operation, they said it's obviously going to be tight, it's 14 days from the operation day till I jump in the car on Friday, but possible.
"Obviously, they don't know what F1 is and the g-forces and everything. Will I be at 100%? For sure not.
"It's not a lie, 100% would mean spending 10 days training, and doing the simulator. I haven't done that over the last 10 days, I've just been focused on recovering.
"But will I be fit to race? The feeling right now is yes, and I'll see how I feel tomorrow and judge tomorrow."
As noted he's missed out on his regular training since Jeddah and given how much effort drivers usually put in it would be expected to be a drawback, but Sainz insists it won't be.
"The amount of training that I did in the winter and how fit I was in Jeddah and Bahrain, actually, thanks to that, I feel like I'm going to be fit tomorrow, because it's not like in two weeks you lose muscle or you lose aerobic capacity," he explained.
"Obviously, it's not the same as spending 10 days training like I would have done and going to the simulator. But that's why I say I'm not going to be 100% fitness level peak, but fit enough to race. I think that that will not be a limitation."
"I also found a lot of support from Alex Albon in this case, because he went through a similar process. I think he got a few extra days than me just because he was operated on a bit earlier. And I asked him, he said yes, you will feel a bit weird at the beginning. But then you get used to it, it's normal.
"So let's see. The problem is I don't know – until you put yourself in an F1 car and feel the forces, it's impossible to know.
"What I know is that today I am a lot better than yesterday, and yesterday I was a lot better than two days ago. So also with that progress, I'm quite encouraged, and positive."
