Audi driver Sainz finished a distant 48th in the 27km stretch in Al-’Ul on Friday, dropping 2m18s to team-mate Mattias Ekstrom who set the fastest time in the sister RS Q e-tron.
This means the Spanish driver will start the rally proper on Saturday firmly in the middle of the pack, and will have to pass a number of slower cars during the stage before he has a clear track ahead of himself.
In an interview with selected outlets, including Autosport's sister website Motorsport.com Spain, three-time Dakar winner Sainz said his strategy for the Prologue was to leave a margin to the front, but he ended up conceding a huge chunk of time when he got lost in the sand.
"The plan was to finish 15th or something like that and the truth is that it didn't work out well because we got lost in one place," he said.
"Then, we stopped before the finish, we made a mistake in the calculation.
"We thought we lost less than we actually did, and when you add in the time we stopped to make sure we were in the top ten, it was too much."
A poor starting position could have repercussions on Sainz’s results in the first test on Saturday, when each crew will have to cover a competitive distance of over 400km to reach their next destination, Al Henakiyah.
"It means, above all, starting from minute to minute, we will have to be patient in the first kilometres and see what we can achieve, opening up a gap, without the dust," he explained. "We're going to suffer a lot.
"The moment you get lost, you don't know how much time you've lost, it's something we've miscalculated and that's it."
However, Sainz remains upbeat about his chances in 2024, stressing how he will have several opportunities to regain the ground he has lost early to his rivals.
"There is still a lot of race left, and tomorrow we have to be patient," said the 61-year-old, who last won Dakar in 2020 with X-Raid Mini.
"If we lose eight or nine minutes, we lose eight or ten minutes, nothing happens. There will be time to recover, the confidence continues, everything is going well, let's see how it goes."
No troubles for Loeb
Meanwhile, Sainz’s former World Rally Championship team-mate Sebastien Loeb made a clean start to the rally-raid, finishing just 38 seconds behind Ekstrom in third place.
It was business as usual for the Prodrive driver, who is still searching for a maiden victory in Dakar in what is now his eighth attempt.
“It went well, no problems on the stage, a very clean special, pushing hard to get a good position,” he said. “In the end, we have a lot of fast drivers behind tenth, so we'll see.
"It wasn't easy, the navigation was tricky, but we had a lot of marks from the bikes because they went out in front. It went well, so it was a good start.”