Daniel Ricciardo says Sebastian Vettel moving to Racing Point next season would put the four-time world champion in "foreign territory" where he would require patience and an open mind.
Vettel will leave Ferrari at the end of the 2020 season and Racing Point is a potential destination for the German.
But a move to the future Aston Martin Racing outfit would most likely force Vettel to downsize his championship ambitions, a predicament experienced by Ricciardo himself when he transferred from front-runner Red Bull to midfield contender Renault.
"For Seb, in his situation he has had pretty much his whole career in the sport running at the front," said Ricciardo who raced alongside Vettel at Red Bull in 2014.
"I would say that probably every year he has contested in F1 he has been on the podium, if not won.
"If it is the case that he goes into a midfield team, it is foreign territory for him.
"It requires a bit more of an open mind, and some patience, but that is up to him and where he sees the next chapter of his career."
At 33, Vettel is far from the sport's average retirement age. But the 53-time Grand Prix winner has made clear that he won't remain in F1 "just to compete", and even less for the money.
"I'm really here to achieve something," he rece,tly told Sky F1. "I will see in the next time whether that's in the cards or it's not. That will drive my decision."
Ricciardo hopes his former teammate will remain on the grid in 2021.
"If he still has the will and drive to compete at the top level, then I hundred percent think he should continue in the sport," said the Aussie. "But if it is in the midfield it is normally a longer play.
"You have to show commitment not just for another 12 months but two or three years.
"But that is something only he could answer. As a previous teammate, I like Seb, I certainly respect him in the sport. That is why if he wishes to continue I hope he finds a place where he is happy."
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