Valtteri Bottas believes the Spanish Grand Prix will be key to the Williams team's hopes of continuing its strong start to the Formula 1 season.
Williams has scored 36 points so far, although the performance of its car means it could have scored more.
With major upgrades planned throughout the field for Barcelona, performance of the Spain upgrades could have a major influence on the competitive order.
"Yes, I think it's going to be an important weekend," said Bottas when asked by AUTOSPORT if he expected what happens in Spain to be key to the team's performance during the rest of the season.
"It's going to give some direction of how the rest of the season is going to be. "If we can make some steps forward, it would be really nice, but it is going to be interesting."
Bottas is encouraged by the fact that much of the upgrade package that Williams tried during the Chinese GP weekend worked as expected.
"We know it's difficult because everyone will bring more updates, it's just a matter of whose work and whose don't.
"The positive thing is that most of the parts we brought [to China] worked and we saw an improvement, so we are hoping to make an even bigger step in Barcelona."
Bottas has scored points in all four races so far this season, but despite this being a significant improvement over 2013, when he scored just once, he admits that there is still room for improvement.
"It's still positive to be consistently in the points but you always want more," he said.
"We just need to keep pushing, keep solving the problems and try again next time."