Red Bull team principal Christian Horner has expressed his concern about the next three races, but is hopeful of better results in the second half of the season.
Daniel Ricciardo has claimed back-to-back podiums to help third-placed Red Bull pull clear of Force India in the Constructors' Championship, but there is still a sizeable gap to the leading duo of Ferrari and Mercedes.
"We're understanding the car better, we're developing the car better and we're getting performance from the car," Horner told reporters in Monaco.
"I'm a little worried about two weeks' time and four weeks' time because they're completely different challenges. The next three circuits for us are actually really tough."
"They are going to be our biggest challenges of the calendar perhaps bar Monza," Horner added.
"If we can perform okay at those next three venues, then with what's in the pipeline for further in the season, I think the second half of the season can be stronger than the first half."