Two of his rivals have admitted they are surprised that Nico Hulkenberg has been ousted by Renault.

The 32-year-old will be replaced for 2020 by Esteban Ocon, who is reportedly on a two-year loan from Mercedes.

"Ocon and Renault clearly liked one another and it was clear that it would happen sooner or later. That's not the surprise," McLaren driver Carlos Sainz said at Spa.

"The surprise is Nico," added Sainz, who was also ousted by Renault after the 2018 season, having served as Hulkenberg's teammate.

"With the leadership he had, Nico did a lot for Renault," said the Spaniard. "He took them to where they are now from where they started in 2016."

Ferrari's Sebastian Vettel also rates Hulkenberg, his fellow German.

"Nico didn't deserve that, but I don't know the background," said Vettel.

"I just hope he will find a car for next season, because a driver of his calibre deserves to be in Formula 1."

Hulkenberg admitted his 2019 season alongside Daniel Ricciardo hasn't been great, but he thinks other factors played into Renault's decision.

"Different drivers are at different stages of their careers, and teams also take into account things like commercial interests and the nationality factor," he said.

"Renault is having a difficult season so perhaps they just decided that a change is needed."

He said it was obvious that "something was wrong" with his relationship with Renault just prior to the summer break.

"Before that, everything was fine. The call came on Monday," revealed Hulkenberg.

The conventional wisdom is that Haas looks like Hulkenberg's best option for 2020. Gunther Steiner confirmed that alongside incumbent Romain Grosjean, he is an option.

"There are not so many good drivers out there," the Haas team boss said.

"We have always said that as a young team we want drivers with experience, and Nico is such a driver.

"I will spend time with Gene Haas here in Spa and again in Monza and it will not be long before we announce something."

Rumours that Hulkenberg holds out hope for the vacant Red Bull seat appear wide of the mark.

"I feel free and relaxed and not under pressure or at risk of falling between the seats," he said.

"There is interest, but of course it has to be right for me. It is still in my own hands," he said.

Both Hulkenberg and Kevin Magnussen insisted at Spa that their prior "suck my balls" episode dating back to 2017 does not mean they cannot work as teammates.

"You do not need to like your co-workers to do a good job," said Hulkenberg.

Steiner, meanwhile, confirmed that Magnussen is already under contract for 2020, and that Frenchman Grosjean has not yet been ruled out.

Grosjean, who has been linked with a move to Formula E, said on Thursday: "I am confident that I will stay with the team next season. For now, Formula 1 is my main plan."