Former Red Bull driver Mark Webber feels Daniel Ricciardo is taking a big chance by banking on the long term with Renault, and the heat will be on his countryman to deliver in 2019.
Like many, Webber was surprised by his fellow-Aussie's shock decision to move on to a team that is currently performing well behind Red Bull Racing, the nine-time Grand Prix winner believing Ricciardo would have been better off remaining with the Milton Keynes-based outfit.
"He's absolutely world class, we know that, he's top notch, he is one of the best on Sundays, there's no question about it," Webber told Fairfax Media.
"Let's see. I hope it's an inspired decision, we'll all have to sit back and watch, but the move is under a little bit of heat, it has to work for him.
"He knows in the short term it's going to be [a step back]. He'll be behind Red Bull next year. He's banking on the long term there. That's the concern."
While Webber views Ricciardo's move as a step back, the 2015 WEC champion hopes it will still be one that will pay dividends in the future.
"That's what you've got to do sometimes, you've got to be one step back, two steps forward," he said.
"He has to be realistic about what's possible there and find out what he can realistically do with the time he's got left.
"He's got a lot of time left [as a 29-year-old] ... but we all would like to see him in a more competitive situation than he's going to be in in the next two years."