Quartararo was classified a distant 19th in the only dry practice on Friday afternoon, finishing 1.2 seconds off the pace set by Jorge Martin on the Pramac Ducati, as he struggled in low-grip conditions on the 2024-spec Yamaha M1.
New team-mate Alex Rins was half a second quicker than him in the same FP1 session, but the Spaniard could only just break inside the top 15 in what was an underwhelming start to the new season for the Japanese manufacturer.
With final practice and qualifying set to take place in similar conditions on Saturday afternoon, Quartararo faces the prospect of being eliminated in Q1 and starting the two races from lower than the fourth row on the grid.
Asked if this was how he anticipated things to be at the beginning of the 2024 campaign, the Frenchman gave a bleak assessment of his form on the Yamaha at the Losail circuit.
"No, I didn't expect to suffer that much in the first practice," he said. "We know that in the test the grip is always super high.
"For us the grip was super-low but looking at the lap times of the others it looks like they don't really suffer. So I didn't expect it to suffer that much.
"Even if we tried something in FP1 that was not really working. I expected to feel a bit better.
"We know what our problem is, where we have to improve but we don't know how to improve.
"When it's low-grip conditions, in the dry or in the wet, we are struggling much more than expected."
Quartararo had enjoyed a relatively better showing at Losail during the two-day test at the Qatari venue last month, ending up 14th in the order with a best effort of 1m51.965s.
It followed Yamaha poaching engineering talent from other manufacturers, including pacesetter Ducati, in its bid to reverse its downward trajectory and return to the front of the pack.
But the Frenchman feels his pace in Friday practice was a step back from the Qatar test, even as Yamaha introduced new parts on the M1.
"In terms of pace in the test I was not top but I was not so bad," he admitted. “But today we were really bad.
“Even if we tried something that was not working, we didn't feel comfortable and this is why I expected a bit better.”
The upgrades in question helped Yamaha to shed some weight off the M1, but Quartararo felt the new package didn’t yield the desired results in Qatar GP practice.
"We have small things, that is an update from the test but it's not something crazy," he revealed.
"It's not something [that is] really helping. We know that our bike is quite heavy and it's something to save a little bit of weight.
"We still have some ideas for tomorrow morning to try and to try to improve this feeling but it's strange to test some settings after two days of testing in this track."
