Australian Webber, who has switched to Le Mans with Porsche, managed to outqualify Vettel only twice in 2013, but the 37-year-old thinks Ricciardo will put up a stout effort this season.
"He'll go well," Webber told the March issue of Motor Sport magazine.
"I think he'll give Seb a real hard time in qualifying -- it'll be 50:50 in the first year, I reckon."
He suggested that the bulk of Vettel's advantage under the former regulations, his superiority in slow corners, was due to Adrian Newey's famous 'blown floor' cars.
"I took a few off Seb last year -- and the blown floor is gone now," said Webber.
"I think Daniel will be fine, and it certainly won't hurt him that he's come through the Red Bull system. I just hope he gets better starts than I did!"