Jean-Eric Vergne says Toro Rosso's Bahrain slump was an "aberration" and expects his team will be back in the hunt at Barcelona.
Vergne and Daniel Ricciardo both have a top-ten finish to their name this season with Vergne finishing 10th in Malaysia while his Australian team-mate was seventh at the following race in China.
However, instead of following that up, the duo failed to score a single point in Bahrain.
While Vergne did not reach the chequered flag after an incident with Valtteri Bottas, Ricciardo just did not have the pace and finished down in 16th.
Vergne, though, believes his team slump was a one-off and that they'll be back in the hunt in Spain.
"It's not long now until we're back in F1 action in Spain, where I'll be hoping for a big push in this European phase of the season," the Frenchman said in his Toro Rosso blog.
"Looking back over the first four races I would say that while it hasn't been fantastic there are positive signs. We have a strong team of good people and they are working well together.
"The car is essentially competitive too, which was shown with my result in Malaysia and Dan's points in China.
"OK, we had a pretty poor outing in Bahrain but I think this was an aberration. Daniel's car was the slowest on track in the race and that's just not right, as he is definitely not slow. Clearly there was a problem elsewhere.
"You have to think about it like this: a car does not go from finishing seventh in a race to being last in the space of one week. The team is investigating it and I'm sure in Barcelona we won't have problems like that."