Red Bull supremo Helmut Marko reportedly "hasn't forgiven" Daniel Ricciardo for the manner in which he left the Formula One team.
Ricciardo walked out on Red Bull to take up a two-year deal with Renault at the end of the 2018 season, leaving the F1 world gobsmacked.
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The decision came around the same time as Red Bull announced they were ending a 12-year association with Renault engines and making the switch to Honda.
Red Bull had become fed up with the underperformance of their Renault engines, which resulted in them being overtaken in the championship by Mercedes.
And According to Sky Sports reporter Ted Kravitz, Red Bull management still haven't fully forgiven Ricciardo for joining their arch-rivals.
Red Bull had a seat vacant ahead of the 2021 season, but never seriously considered bringing Ricciardo back, who signed with McLaren instead.
"It looked like Red Bull weren't going to go back to Daniel Ricciardo, or maybe they just hadn't thought of it," Kravitz said on the In the Fast Lane podcast.
"I think they're still annoyed really, (about) the way he left them actually.
"I think Helmut Marko hasn't really forgiven him, for disappearing off to Renault of all people, which was kind of the final insult.
"If you're going to leave us, OK, but don't leave us for Renault, our dreaded rivals and ex-engine partners."
Daniel Ricciardo begins three-year stint at McLaren
Ricciardo is gearing up for his first season with McLaren, who have also moved from Renault to Mercedes-built engines.
"It's one reason Ricciardo has signed a three-year deal with McLaren, in the expectation it's his best chance of claiming an elusive world title outside of the top two teams," Kravitz said.
"He has to believe it, doesn't he?
"He has to believe that in three years' time this McLaren Mercedes, with such clever things as a trick diffuser and stuff like that, is going to be a team with which you can challenge for the world championship.
"I'd say at this point that would be optimistic."
And Kravitz also made the explosive suggestion that Ricciardo probably won't see out the full three years of his McLaren contract.
"I would be staggered if there wasn't a clause in that three-year contract which said that 'if Red Bull or Mercedes have a space for me, then I can go'," Kravitz said.
"Clearly he's in the business now of getting in a car that can challenge for the world championship. I don't think anyone doubts that he would be able to put a championship together, a campaign together if he had the right car.
"He just needs to wait for the chance. But he knows that something different has to change at Mercedes in order for that to happen.
"Were something weird [to happen], and Lewis Hamilton to retire or [Mercedes] deciding to move Valtteri Bottas on, or both, George Russell is ahead of Daniel Ricciardo in the Mercedes queue."
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