The Enstone team has made a major concept change since last season and knew that it might take time to optimise.
On overall times for the three days, Esteban Ocon and Gasly were 16th and 17th of the 20 drivers participating.
While on balance the A524 is not actually the slowest car in the field, the team is still far from where it wants to be.
"To be fair I haven't really focused on others because there's been so much going on our side," Gasly told Sky F1.
"I don't think we look great. But at the same time, we still have a couple of days to really understand everything we've done.
"We've put the car upside down, done a lot of tests. So hopefully, some analysis and answers will bring us some more performance. And then, we'll find out, no one will hide any more next Friday.
"But I think we'll have to be patient, even if it's not what we like as drivers, but clearly it might take some time before we really unlock the performance we want from that car."
Gasly conceded it will be a difficult start to the season for the team.
"It's not going to be an easy first race," he said. "We're not going to start from where we would have liked. But at the same time, we've got to give ourselves some time to understand that new car concept that we have.
"The good thing is we've identified very clearly what we've got to work on as a team. Now, whether we're able to fix it with car setup or not, for the first few races of the season, time will tell, but for sure there'll be an aggressive plan of upgrades which we will need to close the gap."
Gasly stressed it was important the team understood what it needed to work on ahead of the first race of the season next week.
"It has been very clear with Esteban, we had very similar feedback straight away," he said. "It's all about analysing whether we can fix these issues with set-up ahead of next week, or whether we need bigger upgrades to counter these couple of issues which we can identify already.
"So yeah, a lot of work. Still, it's only three days of testing, it flew by. We'll try to put the car in the best place possible for next week."
Regarding the pecking order, he added: "We're not at the top, that's one thing we know. But then I don't want to make any conclusion now, as I said, it's a new car, there's a lot to understand, there is a lot of performance that we will have to find.
"But right now to make a claim or any conclusion after this much running will not be fair. We'll have to work over the next few days. And hopefully, we'll have a better and more complete car for next week."
