Build-time pressure over the winter resulted in the Silverstone-based marque starting the campaign with a car that is considerably off the pace.
The additional knock-on effect means a delay in the introduction of the team’s B-spec model, which is now not due to be unveiled until the Austrian Grand Prix in June.
The hope is Perez and team-mate Nico Hulkenberg will then finally be able to compete for points finishes, rather than crossing fingers a top-10 spot comes their way via reliability issues for their rivals.
If performance is lacking, however, Perez fears the worst.
“We’re hoping to make a big step forward,” said Perez.
“If we make that step then we can still have a good year as there will be plenty of races remaining, a lot of time to recover.
“But if we don’t make the step we’re hoping for then it’s going to be a very painful year.”
For the team and the Mexican, who was 10th in the season-opening race in Australia – where only 15 started and 11 finished – and 13th in Malaysia recently, the current struggles are already tough to endure.
“It is frustrating knowing we don’t have a competitive car that can take us into the points on pure pace. It’s really hard,” said Perez.
“It is also really hard to keep motivated. Going into a race, knowing it is going to be very hard without any advantage, is not the easiest for a driver.
“At the moment, on pure pace, it is quite difficult to make it into the points. We’re quite far from the teams ahead of us.
“We are in a position where it’s very easy to make mistakes, to lose the car as it is very difficult with degradation and stuff.
“From now on we are going to have hard races, but it is what it is at the moment.
“We have to be professional and do the job as if we are going to win the race.
“We’re going to give 100 per cent and try to be there with whatever we have, to try to get into the points before we get the new package that can hopefully get us back into the points on pure pace.”