Sergio Perez fears Force India could be in for a "painful" Formula 1 season unless the delayed B-spec car proves to be a significant step forward.
The Silverstone-based squad was the last of the teams to run its Mercedes-powered 2015 car, and arrived in the season-opening Australian Grand Prix after just one test with it.
Force India plans to introduce a heavily updated B-spec version of its car, but it was revealed this week that it will be delayed at least until the Austrian Grand Prix, the eighth round of the championship.
Although Perez says Force India can still salvage its season by then, the Mexican admits the car will have to be a clear step forward.
"If we can make a proper step then I think we can still have a good year, because there are plenty of races to go after that, so there's a lot of time to recover," said Perez on Thursday.
"But if we don't make the step that we are hoping for then it's going to be a very painful year."
Motivation a problem
Perez said it will be hard to start the European season in Spain with no significant updates while most of its rivals plan to bring big upgrades.
"It will be hard, but I don't think it will be harder than it is at the moment," he said.
"We are fighting for the last positions, but who know what happens in every race."
The Mexican, who finished in the points in Australia but down in 13th in Malaysia, admitted it was hard to stay motivated with an uncompetitive car.
"It's really hard to keep motivated going into a race knowing it's going to be a really hard race.
"It's not the easiest position as a driver for you have to be be professional and you have to do the job as if you were going to win the race."