Formula 1 teams are racing away from taking a punt on rookie drivers, according to Haas boss Gunther Steiner.

Steiner notoriously grappled with the frustration of Mick Schumacher's struggles last year until he made the decision to replace the 24-year-old German with his more than decade-older countryman Nico Hulkenberg this year.

"Then you look at Nyck (de Vries), who is not a bad driver," he told Ekstra Bladet newspaper, referring to the rookie Dutchman who has just been dumped by Red Bull and Alpha Tauri.

"But he didn't make it. They've brought back 'Danny' (Ricciardo) who didn't deliver what he is capable of last year. He will admit that himself.

"But they brought him back maybe because they saw how it worked for us. Where Formula 1 is right now, potential is a difficult quantity.

"You need to find someone who is really, really good. Take Oscar Piastri. Fair play to him, he is obviously exceptional. But it's getting harder and harder for rookies to get into this sport.

"All the teams are good now. There are no hopeless teams so it's so very important to have good and experienced drivers. And it's even more important at this end of the grid because we are so close together.

"No one can take a rookie for 10 or 15 million anymore. It's not worth it. So it's even more difficult to get new talent from F2 into F1. Because no one dares to take the risk," Steiner added.

"Look at Aston Martin - they took a 41-year-old with a fantastic result. Hopefully it doesn't go too well for Alpha Tauri now, but they've done the same as Aston and us."

It means there are no longer any sure-fire routes into Formula 1 from other categories, Steiner argues.

"They need to be extraordinary talents to come from F2 now," he said. "If you've been in Indycar for five years and you're good, you're good. But it's hard to measure how good.

"In F2 and F3 now, even the winner is sometimes not so good if the competition is not good enough."

So as Alex Palou makes waves with a dominant performance in Indycar this year - a title he already conquered in 2021 - Steiner thinks the Spaniard will struggle to convince an F1 team.

"I think Palou is really good," he said. "Wherever he has driven. But someone has to take the risk now.

"Look at Romain Grosjean, who has gone above and beyond over there and hasn't done much. In Formula 1 he was pretty good. So there are too many unknowns.

"Until someone tries it in practice, we won't know. But no one does anymore because it's too risky."