• Verstappen will challenge for 2020 title, according to Webber
• Ferrari not a threat in 2020
• Red Bull's only 'question' is its Honda power unit
Webber told Ziggo Sport: "In reality, it will be between (Max) Verstappen and Lewis (Hamilton)."
The sport's 'corona calendar', set to kick off after a long shutdown, will begin next weekend with back-to-back races in Austria.
Do you agree with Webber that Verstappen will be Hamilton's greatest challenger this year? Email us.
'Not even Ferrari'
Webber continued: "I don't see anyone else being a real threat, not even Ferrari. And no one else can challenge Lewis other than Max."
43-year-old Webber knows Red Bull well, having served as Sebastian Vettel's team mate throughout the championship-winning years.
He says the team can now beat Mercedes.
He concluded: "Yes, I believe in the way Red Bull operate as a team and their aerodynamics. The only question is what Honda can do against the Mercedes. The Mercedes engines are probably still stronger, allowing them to use bigger wings and make life easier for the drivers."