Ferrari will "completely write off" the 2021 season, Mercedes team boss Toto Wolff predicts.

Ferrari, having badly underperformed in 2020, is building a new engine for next season but Wolff thinks the Maranello team will put most of its attention next year into the all-new rules and cars for 2022.

The aerodynamic rules are being slightly tweaked for next year, under a 'token' system of limited car development.

"I don't think the ranking will turn upside down," Wolff told the Austrian broadcaster ORF.

"There will be teams, like Ferrari, who will completely write off 2021," he predicted. "They will develop their cars for 2022 from the beginning."

As the reigning champions, Wolff said it will be a slightly different story for Mercedes.

"It is of course quite difficult for us to find a good balance between 2021 and 2022," he admitted.