However, when asked about his Hamilton's chances for his new team, Verstappen - who himself is bidding to emulate Michael Schumacher by taking five consecutive crowns - said: "I don't need motivation from anyone else but it (moving to Ferrari) is nice for Lewis.
Hamilton will get his first proper taste of the machine he hopes will deliver him a record eighth world title and Ferrari's first championship in nearly two decades, at the sole winter test in Bahrain next week.
He ended his two-and-a-half year winless streak at the British Grand Prix last July, but finished only seventh in the world championship, 214 points behind Verstappen, following a disappointing final campaign with the team that carried him to six of his seven titles.
"If Lewis gets off to a good start and he gets the team around him, he will find his confidence and he could be a real contender for this world championship," said Horner.
Lewis Hamilton will be "reborn" at Ferrari, his rival Max Verstappen claimed at Formula One's glitzy season launch in London.
