Doohan ultimately crossed the line in 20th and last in the Chinese GP Sprint following a late tangle with Gabriel Bortoleto.
It left the Sauber driver pointing the wrong way in a clash the Australian picked up a 10-second post-race penalty for.
That came at the end of a 19-lap race where tyre management was critical.
“It has been quite a tough day and we will regroup as a team and focus on having a more positive one tomorrow,” Doohan said after Qualifying.
“This morning’s Sprint Race was one where we focused on learning about the tyres and, in the end, it was a difficult one to make progress with the DRS train and quite high tyre degradation.
“We learned a lot from the session in preparation for Sunday’s race.”
The Shanghai International Circuit has been resurfaced ahead of this year’s event.
It offers far more grip, with Oscar Piastri’s pole position lap the fastest time ever recorded around the venue, but at the cost of high degradation.
With long, loaded corners, it’s proved tortuous for tyres – more so when running in traffic.
“The most part of it, to be honest, is going to be trying to find free air,” Doohan said of race.
“That’s going to be the most important as, at the end of the day, you’re not really going to be in free air.
“But try and help that front-left tyre, what everyone’s struggling with, is going to be the most important thing.”
Doohan lines up 18th for today’s race, two places back from Alpine teammate Pierre Gasly.
The Chinese Grand Prix begins at 18:00 AEDT.
