A former Red Bull driver has expressed concerns about the F1 team's technical future.

After Singapore, Dr Helmut Marko said a simulator error led to a setup problem that cost Max Verstappen a chance of winning the night race.

Verstappen called the weekend a "wake-up call".

Just days earlier, it was announced that Red Bull's legendary technical boss Adrian Newey is teaming up with Formula E champion Jean-Eric Vergne to create a new 'Extreme E' team called Veloce Racing.

Newey was revealed as the team's "lead visionary".

Robert Doornbos, who raced for Red Bull for a period in 2006, thinks the development is alarming news for the Honda-powered team.

"That man is a genius," Dutchman Doornbos told Ziggo Sport. "I think he has nine world titles to his name.

"Basically everything revolves around him. But what I hear now is that he is working much less (at Red Bull), not committing himself 100 per cent.

"He works on external projects such as the Aston Martin Valkyrie and now a team with Jean-Eric Vergne," Doornbos added.

"I think when an entire organisation revolves around one man and that one man is not completely there, you will experience problems."

Doornbos also said Verstappen could be nervous about Newey's diminishing role at Red Bull Racing.

"Of course we know that Max has no patience," he said. "I can only agree with him.

"After all, he can easily keep up with the other guys around him -- it's the car that holds him back."