Asked in a Q&A by a reader of F1 Racing whether he would let Alonso pass in the final laps of a race if it meant the McLaren driver winning the world title, Sainz said he was pretty sure he wouldn't do it.
"Look, it is probably the worst question ever to answer... [sigh and long pause] but, when you drive in Formula 1, you see a McLaren behind and you don't see Fernando Alonso, the person. You see a McLaren that you're sweating your balls off to beat.
"So on the last lap I am not just going to let him by, especially if I am in P3 and about to get the first podium of my career, or my first win or whatever.
"So I wouldn't enjoy it as much, because I'd know Fernando would have been world champion for a third time and it's what I wish him for next year. A very hard question. I shouldn't have looked at this one."
We honestly wouldn't expect anything less from a racer worth his mettle, although Sainz competitive attitude takes nothing away from the respect he feels for his role model.
"Everyone knows about the admiration and respect I have for Fernando. Not only because of his success, but because of how he has treated me since I was just 10 years old.
"He has always supported me. He's always said that I'll be the next best driver from Spain and I will always be very grateful for that. We are good friends."