Gasly will start today’s race from 10th, Alpine’s first top 10 start of the year, a result which was a sharp improvement following a disappointing Friday.
The Frenchman lost running on the opening day courtesy of a wastegate issue that took time to resolve.
It meant he was left making up for lost time in Free Practice 2 as he got comfortable in the car and confident on the Monaco streets.
However, it was an overnight stint put in by Doohan back at the team’s Enstone base that helped transform his fortunes on Saturday.
“Jack did a very good job in the sim,” Gasly revealed.
“I told him this morning, he arrived with very small eyes, but I told him it was very useful in some of the directions.
“I had clear directions in which I wanted to go with the car and it just confirmed that sort of feeling from his test.”
Doohan is Alpine’s reserve driver, and along with being on standby to fill if needed at the track, he routinely supports the race drivers on the team’s simulator.
On Friday night, that saw him work into the wee hours before jumping on a plane and heading to Monaco – getting little sleep in the process.
“The first Q3 of the year for us amazing results for everyone here and everyone in the team,” Doohan told Speedcafe.
“No easy feat. Yesterday was not our easiest to start to a weekend.”
Following a day’s on track running, teams feed information back to base where they’ll continue working in the virtual world.
Doohan completed a lengthy programme that saw him trying alternatives based on feedback from Gasly and Esteban Ocon.
The outcome was a long night that netted a tangible result.
“We got sent through a lengthy and thorough programme that we had to get completed with many test items,” Doohan explained.
“As it is, not everything does work and not everything is a bonus, but we kept our heads down, we found a few good points that seemed to really focus on the areas that we needed to improve.
“And the boys were happy to apply them today and really get comfortable in those areas that they were struggling on, particularly in braking, ride, and entry instability.
“It was great that we’re able to take the step that we did. And that end result really wasn’t our true potential, so it’s good to know that but still, we’re aiming for some solid points.”
Doohan’s efforts were also called out by team boss Bruno Famin, who praised the young Australian.
“We made some improvements from yesterday through to today,” Famin said.
“Credit must be given to the simulator work at Enstone and our reserve driver Jack Doohan who did a great job overnight to try a few things out and improve the car set-up.”
Those gains helped give Gasly the confidence to push on when it came to qualifying, delivering the team’s best result of the season thus far.
“It’s a track where you need to nail the quali lap,” he explained.
“I felt connected with the car. I felt confident. That’s why I think I pushed that hard.
“I don’t think I’ve ever pushed the limit as much as I did this year. I just felt that the car was giving me what I needed.
“It was nice to kind of feel that connection here in the streets of Monaco.”
The Monaco Grand Prix starts at 15:00 local time, 23:00 AEST.