Nyck de Vries' Formula 1 career is still under a very dark cloud.

That is the admission of two of his well-known Dutch compatriots, even if the 28-year-old rookie showed signs of improving recently after a warning from Red Bull's Dr Helmut Marko.

Dutch racing driver Tom Coronel, however, admitted to the Dutch publication Formule 1 that it is clear de Vries is "not yet worth the investment" to Red Bull and Alpha Tauri.

De Vries' shaky place on the F1 grid only looked even shakier after his failed wheel-to-wheel battle with Kevin Magnussen in Canada.

"He never made room for Magnussen," said Dutch GP boss and former F1 driver Jan Lammers. "Then Magnussen had to leave the circuit to prevent them from hitting each other," he told NOS.

"It got worse after that, because at the next corner, I think he was disoriented because it's not a corner you can normally overtake at. Nyck braked too late, Magnussen braked on time, but he couldn't turn in because Nyck was there.

"The race management I think was lenient with Nyck."

Lammers says it's a gift to Zandvoort that there will be two Dutch drivers at the Dutch GP this year, but he also admits that de Vries' short career could be over by then.

When asked if the Alpha Tauri driver will still be in the cockpit after the summer break, Lammers said: "I don't want to participate in that.

"I wish the best for everyone, including Nyck. But Red Bull is merciless so he has to perform."

Lammers says de Vries' situation is similar to that of Alex Albon in the past - when Red Bull ousted him out of F1 and into the German touring car series DTM.

"Albon was in the same situation as Nyck," he said. "He got a new chance and now he is driver of the day - who would have thought that?

"But to achieve something like Albon, de Vries needs more time. Will he finish the year? I don't dare to say that."

F1 correspondent Louis Dekker thinks de Vries' obvious successor is already waiting in the wings.

"Liam Lawson can jump in right away," he said. "So the mistakes (of de Vries) have to stop. Time is really ticking.

"As soon as a driver costs millions and he doesn't score any points, it's over quickly. Zandvoort is the first race after the summer holidays and it's in the summer that the teams will be looking at what they will do next year."

Lammers commented: "With Albon, the bad things were bad, but the good things were better. Nyck needs that too.

"A good race must therefore be a very good one, but it is up to him to do it." body check tags ::