Fernando Alonso believes Lewis Hamilton's move to Mercedes is a change for the better.
Hamilton confirmed last week that he is to leave McLaren after a career that has been so far supported by the British squad.
He made his F1 debut with the team and took his first title in 2008 with it.
Alonso, now at Ferrari, partnered Hamilton at McLaren in 2007, but left at the end of that season after a turbulent year and a spiky rivalry between the pair.
"I think it's normal. It's a step in your career," Alonso said at Suzuka on Thursday.
"I think for Lewis it is a good thing to move on and for McLaren .... [Alain] Prost went out, [Ayrton] Senna, then it was me, now it's Lewis, and normally for a better life, for a good change.
"McLaren has been 14 years without winning the constructors' championship, most of those years sometimes with the best car. I'm sure Lewis wants to win as well."
Although Mercedes has failed to be a regular contender for victory since its return to Formula 1, Alonso has no doubt that Hamilton will be fighting for the title right from the start.
"I think he did great in McLaren. He won one world championship. He won races," said Alonso of Hamilton.
"He is considered one of the best drivers, and I think next year he will enjoy it more. He will be very competitive, and I think from next year he will be a contender for the championship.
"Mercedes is a top team with Ross Brawn there and all the potential of a big company behind. So they are strong."