Max Verstappen has said that he is worried not only about Red Bull's performance this year, but also for 2018.
The young Dutchman is already under contract for next year, but after retiring in Montreal he insisted that 2017 has been "completely crap" so far.
Team boss Christian Horner excused the 19-year-old, though.
"He knows how hard the team is pushing to make the car better. He'll see the big picture," the Horner said.
"We were racing against a Mercedes [in Canada] and we beat Ferrari. Max hasn't had the result but it's still a long season. His time will come."
Yet Verstappen said that his concerns are not just about 2017, particularly following the latest news from engine partner Renault.
"We wanted to go for the world title this year, but we are far from it," he told Dutch broadcaster Ziggo Sport Totaal.
Renault has now said the power unit will not be significantly updated for the rest of the year, and Verstappen admitted: "I'm worried, also for the direction for next year.
"I want to win and I absolutely think this team can. You can see we have improved the car a lot. But the power is yet to come.
"And right now, as you may have read, there will be nothing more [in 2017]. Updates were promised but there have been few."
Red Bull remain third in the team rankings, some 102 points adrift of second-placed Ferrari.
