Although the Woking-based team had come off second best to Max Verstappen in the Brazil sprint race, it felt that it had a much better chance in the main grand prix.
And following Norris' brilliant start in the original getaway on used softs, as he jumped from sixth on the grid to second by the first corner, McLaren says its mindset totally changed when the red flag came out as the result of the first corner crash involving Kevin Magnussen and Alex Albon.
PLUS: The crucial lap that swung F1's Brazilian GP from Norris to Verstappen
Rather than playing it safe at the restart, and sticking to the used softs it had for the original start as Verstappen did, it went for a completely new set as it felt it could give it a sniff of the win if Norris could surge into the lead when the lights went out.
McLaren team principal Andrea Stella explained that the squad felt the tyre offset was worth a gamble as it could just be enough to overcome what it felt was a small deficit to the Red Bull.
"I think certainly in terms of our approach, especially after the red flag, we wanted to win it," explained Stella when asked by Autosport if it felt it had a chance of beating Verstappen at Interlagos.
"At the start, we put our best set of softs on, so we decided to start on a new set, so we could try and take the lead. And from there, [perhaps] put Verstappen in an unusual position and see what we could do. Maybe we could just cover anytime he pits and so on."
But McLaren's plan fell at the first hurdle, as Norris found himself outdragged by Verstappen on the run to the first corner.
And although the Briton was able to shadow Verstappen in the opening laps, and even briefly launch a challenge, McLaren quickly realised that following too closely was overheating the tyres – so it needed to back off.
Stella added: "We couldn't take the lead at the launch. We went very close to doing it on track, but after that our tyres started to overheat and we needed to think about achieving our target lap times, because [Fernando] wasn't that far behind at that stage and it seemed like he could stay with us.
"Certainly, we tried hard in the first stint. I think after that, Verstappen once again, he had enough lead to actually manage the situation.
"I think anytime we tried to get a little closer, even there were a few laps in the second stint in which we seemed to go [closer], then he could put together a couple of mega laps. After the first stint, there wasn't very much we could do."
Having seen how the sprint had turned out on Saturday, as Verstappen seemed able to manage the pace over the long runs as Norris pushed from behind, Stella was well aware that the start was the only opportunity to really do something different.
"That's why we wanted to take the lead on new tyres, and try to change this kind of destiny that would have happened with Verstappen leading race," he said.
"We wanted to break this kind of continuity with [Saturday] but unfortunately, we missed it. Not by very much, but maybe one metre, to be able to actually pass. After that, it was pretty much a repeat [of the sprint]."
Norris himself accepted that once Verstappen was running comfortably in front, there was very little he could do to challenge him as the Red Bull appeared better able to look after its tyres.
"It was similar to what we saw in the sprint," he said. "I'm not far behind for the first 10-15, 17 laps but that final phase, I just drop off a bit too much.
"I don't know if it's just we're a bit slower and I'm pushing a bit more to try to keep up, and then I pay the price, or it's just a little bit of our tyre degradation is not quite as good and we suffer in the slow speed, quite a bit with the rears.
"That's where we struggle then with the lap time in the end. So, yeah, clear things to improve on."
