Stoffel Vandoorne has said that he is not sure McLaren will be ready to win races in 2017.
After two seasons of struggle but steady improvement, the Honda-powered team have announced that they will launch their new car on February 24 - the same day as Ferrari.
There is already speculation that the car will be in McLaren's traditional orange.
Ron Dennis was always opposed to racing in McLaren orange in the new era, but the long-time McLaren supremo has been ousted and new executive Zak Brown has hinted at a livery change for 2017.
At a Richard Mille sponsor event, a McLaren was coloured in a "one off" black and orange livery, and the same graphic theme was used for the announcement of the 2017 launch on Monday.
As for how competitive the car will be, Belgian rookie Vandoorne is not sure.
"It's hard to say," he told La Derniere Heure. "It's too early to judge.
"In any case, McLaren is improving. The last two seasons were not easy for Honda, but we made a significant step forward and we hope that positive trend will continue.
"I hope the car will be competitive and we will fight for the top positions."
Last year, Fernando Alonso finished 10th overall, so asked if that is good target for 2017, Vandoorne said: "No, finishing in the top 10 is not the goal. I want to win.
"But we don't know if we can win races already. Probably this year it won't be the case, but I'm still going to try. McLaren has good prospects for the future and I'm in the right place. I believe in the team."
McLaren ended 2016 with 76 points, up from 2015's 27.