Oct.7 (GMM) Sebastian Vettel has admitted he was "very surprised" when he heard Lewis Hamilton had signed up with Mercedes for 2013.
"It's difficult to judge from the outside," the German is quoted by Spain's El Pais newspaper.
Asked if Hamilton might be just as 'dangerous' in his new silver car in 2013, the Red Bull driver answered: "We'll see what happens.
"Lewis is going to a good team, so it will be a good combination, so I wouldn't say he won't be in the battle for the title," said Vettel.
The German, however, plainly blames Mercedes for friend Michael Schumacher's failure to shine during his three-year comeback.
"He is a great loss to F1," said Vettel, "but for me the problem was that Mercedes was not among the fastest.
"If you put him in a good car, it's hard to believe he would be anything other than competitive."