Pierre Gasly says his unexpected early exit from qualifying at Mugello was mainly due to a lack of energy deployment caused by pushing his AlphaTauri's engine too hard.
Last weekend's Italian Grand Prix winner was confident of securing a spot in Q3 in the Saturday afternoon session based on his car's performance in free practice.
But the tightly bunched midfield in Q1 meant that any glitch would prove costly, and Gasly suffered the consequences of poor energy management coupled with set-up issues for his AT01.
"Today was frustrating as everything was going so well all weekend," lamented Gasly.
"The car was good in free practice, and in quali we pushed the engine a bit more and in my two laps before the finish line. We missed it for half a tenth and we lost over a tenth with the deployment, running out of SOC (State of Charge) way too early before the line.
"We also made a few [setup] changes after P3 which didn't go in the right direction, and we are still analyzing why we basically went slower than P3. There is less fuel in the car so we lost grip and we can see it, so we are still investigating.
"But I'm not blaming anyone. I'm just saying us as a team didn't do the perfect job today and, with the margins of half a tenth, it is nothing. But today the few little mistakes we did clearly cost us a lot."
Unfortunately, the P16 low qualifying spot means that F1's Monza winner will have his work cut out for him on race day.
"It’s clearly not good on such a track to qualify so far behind and it’s a shame because everything before that went great.
"We just didn’t manage to put things together in quali and we made small mistakes in the worst possible moment.
"We need to find a way to recover as we know we are faster than this, so we’ll try to make our way back into the points tomorrow."
AlphaTauri tech boss Jody Egginton says the team has made its life for the race unnecessarily complicated.
"There is a lot of work to get through tonight in order to be fully prepared for the race, and today's result has made it harder than it should have been," said Egginton.
"However, we feel we have a package to be competitive tomorrow fighting with the cars in the midfield and this is our target."