- Mercedes duo favorites to fight for F1 title
- "Hamilton will be dangerous," says Webber
- Rosberg had end-of-season momentum
- New season begins in Australia on March 20
(CNN)It has been a long winter for Mercedes' dueling drivers.
Formula One world champion Lewis Hamilton has been training for the new season in the boxing ring and on the basketball court.
His arch-rival Nico Rosberg, who won the last three races of 2015, was busy babysitting his baby daughter Alaia at home in Monaco.
After a winter of waiting, the duo will renew their rivalry at the Australian Grand Prix on March 20 -- but will Hamilton deliver the knockout blow, or will Rosberg prove he's "The Daddy"?
"If the Lewis Hamilton we know turns up, hungry and fired up, he'll be dangerous," former F1 star Mark Webber told CNN's The Circuit.
"But if Nico can keep up the momentum into 2016, he can start the season really, really well."
Ferrari clocked the headline times over eight days of preseason testing in Barcelona, with Kimi Raikkonen owning the fastest lap overall of one minute, 22.765 seconds, set on 2016's new ultra-soft tire.
Mercedes, however, covered the greatest distance -- the equivalent of more than 19 grands prix -- and was strongly suspected of saving its true pace until Australia.
Rosberg ended last season as "Mr. Perfect," claiming six pole positions and three wins in a row to leave Hamilton trailing.
But the German was only able to assert his dominance after Hamilton had already won the world title at the United States Grand Prix in Austin, a victory sealed when Rosberg made a mistake and ran wide in the closing stages.
"Lewis backed off a sniff, two or three percent, once he'd won the championship," adds Webber, who retired from F1 at the end of 2013. "Nico was thinking, 'I've got to finish with some momentum and ramp it up.'
"I was impressed with how Nico pulled it back at the end of last year. All of a sudden he had this swing in performance and could do no wrong.
"If Nico can keep that up for the first half a dozen races of this year, he will do really well.
"If Lewis turns up wanting to make a huge difference and forgetting the numbers he's already got, he can win. But that's up to Lewis -- he knows he's got to deliver."
Webber is speaking from bittersweet experience. The Australian raced against a teammate who had no problem finding the motivation to rack up four world titles in a row.
His relationship at Red Bull Racing with Sebastian Vettel was famously fraught, and the parallels between Hamilton and Rosberg's dynamics are clear.
Vettel is now racing for Ferrari and aiming to stop Mercedes' quest for a third straight title. The Ferrari ran well in Barcelona but there were already clues that the title will be once again decided by an internecine battle at Mercedes.
"When it really is just the two of them (fighting for the title) it is very easy to get wrapped up in yourself," reveals Webber, who won the World Endurance Championship racing Porsche sports cars in 2015.
"You know that just across the table there's a guy working with very similar equipment, with the same resources and people to get the same out of the car.
"(You think) what is he doing? Have I got something up my sleeve that I don't want to show?
"There were a few years when Seb and I had company and it was more open between us because we needed to stay ahead of everyone else.
"But when it's not like that, then the tension can build even more because it's only the two of you."
Hamilton has used Mercedes' era of dominance -- sparked by major engine rule changes in 2014 -- to his advantage, winning back-to-back world titles to add to his 2008 success at McLaren.
The 2014 title, however, was only settled at the final race of the season in Abu Dhabi, and Rosberg will be determined to hang in the fight in 2016 against F1's newest pugilist.
Webber raced alongside Rosberg at Williams in 2006 and gave the rookie a few pointers, but he reckons the 30-year-old now knows all he needs to about handling a feisty teammate.
"He's seen a lot of the movies that I've seen, with Lewis in Sebastian's shoes," Webber says, in his typical straight-talking style.
"We've had some interesting chats in the past. Now, the advice I could give him would be very limited.
"A little bit like myself, Nico went through a stage of struggling with starts. It's all good qualifying on pole but you've got to get to the first corner first.
"Now he's got the starts going and there's all these one-percenters which he is more than aware of now. He doesn't need me to tell him what to do."
Melbourne's Albert Park, a bumpy street circuit around a lake, has provided victories for both Hamilton (2008 and 2015) and Rosberg (2014).
"It's a great atmosphere in Melbourne," Webber smiles. "It's the first race of the year, we've got new car color schemes, and we've got drivers ready to go with sexy new helmets. It's exciting times!"
Whether it will be a good time or a bad time for Hamilton and Rosberg will be decided when the checkered flag falls.