SUPER-QUICK Nico Rosberg will provide a stern test for his teammate Lewis Hamilton at the improving Mercedes team this year as he seeks his maiden world title.
The German finished sixth in last year's championship and won twice for his team at Monaco and Silverstone, as well as two other podium finishes in India and Abu Dhabi.
He finished 18 points behind Hamilton in last year's title race and was only narrowly out-qualified 11-8 across the season as he continues to improve.
If Mercedes, which finished second in last year's constructors' standings, can keep moving forward after a strong pre-season then Rosberg could be a contender to emulate his father Keke, the world champion in 1982.
Rosberg, 28, has three wins and four poles over his career and is likely to benefit from the technical experience at Mercedes this season.