Nov.21 (GMM/ Toto Wolff is sure Mercedes’ in-house battle for the biggest prize in motor sport this weekend will not boil over.

Nico Rosberg on Thursday was piling on the psychological pressure, even urging Lewis Hamilton to keep their on-track fight “clean” in Abu Dhabi.

Of the duo, with Hamilton 17 points ahead and only needing to finish second, it is Rosberg playing the more obvious “mind games”, although there was a tense moment in the FIA press conference when Hamilton appeared reluctant to shake his German rival’s hand.

“He has everything to lose and I have everything to gain,” Rosberg said.

He claimed Hamilton only spun in Brazil two weeks ago because he was feeling the pressure, and even vowed to make Hamilton “nervous” in their internal team briefings throughout the decisive race weekend of the season.

“That’s my job this weekend,” Rosberg told German reporters on Thursday. “It helps, of course, that we’re always around each other most of the time.”

He also suggested that he may depart from his usual routine and experiment more with his car setup in Abu Dhabi, and noted that last year in Abu Dhabi “was one of his (Hamilton’s) weakest races”.

Observers on Thursday concluded that Rosberg appeared more bullish on Thursday, while Hamilton talked of feeling relaxed but kept his answers to the media short and quiet.

“In terms of the pressure, I don’t really feel anything,” the Briton insisted. “I have been racing for 20 years to prepare for it.

“The last time I was in this situation I was nervous. Now it’s like being a kid at Christmas.”

No one really believes Hamilton is feeling that way, but his 2008 championship rival Felipe Massa knows how important trying to relax is.

“If you’re scared, you lose tenths,” the Brazilian said.

“Hamilton is in a simple situation but in the race he needs to be careful, which does not always work out for Lewis. Let’s see how it ends.”

Wolff, the Mercedes team boss, said the German team is impartial and only wants the title to be decided fairly.

He is not worried a Senna-Prost style collision will happen.

“They are both good lads, neither of them are deceitful,” Wolff is quoted by Spain’s Marca.

“Nico has to win and Lewis wants to win (the title) with a victory so it will be a tough race,” Germany’s Auto Motor und Sport quotes Wolff as adding.

“But it will not go so far that they will drive into each other. They both have too much to lose.”