Force India remains unsure on when its latest upgrade package will be ready to race - with the team not yet guaranteeing it will have the parts ready for this weekend's Spanish Grand Prix.
The team has a series of development parts in the pipeline that it hopes will lift its car performance, and it tried out a new front-wing concept in Friday practice at the Turkish Grand Prix.
But with rain having washed out that day's running, the team did not get enough mileage on the parts to be sure of their benefits - so it elected not to race them at Istanbul.
Force India team principal Vijay Mallya said on Monday that the team was still evaluating whether the updates will reappear on the car in Spain this weekend, or if the team will wait until the Monaco Grand Prix later this month.
"The Spanish Grand Prix is always a significant moment in the season," said Mallya in a Force India team preview.
"It marks the return to Europe and it's the moment when the Formula 1 development race really begins. At Force India we have some upgrades to bring to the car in the coming races and I'm excited to see how things will unfold.
"We started evaluating those changes at the last race in Turkey by running a new front wing during free practice. It was a shame that it was wet because it limited our test programme and we chose not to run those new parts for the race.
"We are now analysing what we learned and hopefully we can add this new package to the car either in Barcelona or Monaco, depending how things go. When our new aerodynamic developments are in place, I'm confident we can take a step forward in terms of performance."
Paul di Resta believes the team needs to make steps forward if it is to continue fighting for points - which is why he is looking forward to getting the new wing on the car as soon as possible.
"It's usually a race where all the teams bring upgrades so we will need to take a step forward if we want to stay in the mix," he said.
"We evaluated a new front wing in Istanbul and we hope to have more steps coming through in the near future. The team has been working hard on this new concept and everybody is quite upbeat about its race introduction, so that's something to look forward to."