Lewis Hamilton believes Sebastian Vettel has no interest in becoming his team-mate at Mercedes as it would not be as comfortable as life at Ferrari.
Vettel is out of contract at the end of this season and is still in negotiations with Ferrari over a new deal. There is a question mark over the length of the new contract, with the four-time World Champion possibly wanting to keep his options open for 2019.
Hamilton, though, feels Vettel will never join the Silver Arrows as long as he is there because it is a rivalry that the German would not want to get involved in.
"I think it is highly unlikely that he will be here (at Mercedes), and I don't think he wants to be my team mate," Hamilton told reporters ahead of the Belgian Grand Prix.
"I know he doesn't want to be my team mate.
"He would not be in the position he is now in his team, in terms of how the team operate, if he was here.
"I'm always game to race whoever it is, and racing against the best drivers is always a great thing."
It is believed that Vettel would stay at Ferrari for next season at least on the understanding that Kimi Raikkonen, who he has dominated this campaign, would also be retained.
Ferrari announced a new one-year deal for the Finn on Tuesday.