Wolff: Mercedes driver rivalry to 'intensify' in 2015 F1 season

Hamilton beat Rosberg to the 2014 F1 title after a battle that included several on- and off-track flashpoints.

The 10 moments that decided the 2014 title

Wolff believes both will have learned from mistakes last year and will return for 2015 with weaknesses addressed.

"I think they rate each other, they respect each other on track and I have no doubt that the battle's going to intensify," Wolff told AUTOSPORT.

"Both have learnt, both will ramp up their game in comparison to the other one.

"They will try to cure weaknesses and work on their strengths and for us it's a great situation because it helps the team to perform and it helps the car go faster if the two are pushing each other."

Asked if he thought the intra-team competition would be even closer in 2015, Wolff replied: "Well it cannot go much closer than last year. I must say I wouldn't want it to go much closer."

Hamilton has yet to agree a new deal with Mercedes beyond 2015, and his private life has also been the subject of renewed media coverage over the winter.

Wolff denied that these factors would have any impact on Hamilton's mindset going into the new season.

"I can only tell you how I've seen him; very professional, in good spirits, we have good discussions," he said.

"We're not trying to interfere too much into the private life.

"I think both of them are on a level where they know what they need in order to perform - they're completely different.

"I haven't had a moment of doubt if Lewis was in good shape. He absolutely is.

"I have seen a very strong, clear and motivated Lewis Hamilton."

Mercedes begins the 2015 season as strong favourite for another title double, after outpacing all rivals in testing despite not using the supersoft tyres on which most teams' best laps came.

But Wolff dismissed any suggestion that Mercedes had already unnerved its opposition.

"Is it really like this?" he said. "I wouldn't really try to read too much into laptimes because we don't know what fuel loads people were running."