Fernando Alonso said Lewis Hamilton's move to Ferrari could turn the Italian team into championship contenders in 2025.
Alonso added his "first priority" if he stays in Formula 1 after this year would be his Aston Martin team, before considering the seat Hamilton leaves at Mercedes.
The Spaniard said: "[During the past few years] Ferrari had a very fast car and were fighting for big things.
"Maybe Lewis can bring that extra to fight for the championship. The car is there."
Alonso, who said he believed the new Aston Martin "should be a good step forward", pointed out that Ferrari took more pole positions than Red Bull over the final five races of last season.
"Even last year, with a very dominant Red Bull car, Ferrari were able to match the lap time and be faster than them in most of the qualifyings, so the car should be fast enough," he said.
But he questioned Hamilton's claim that driving for Ferrari was a "childhood dream", alluding to recent comments in which the Briton said he wanted to be with Mercedes for the rest of his life.
"It was not his childhood dream 12 months ago, no? Or two months ago I guess, because it was a different dream then," Alonso said.
The 42-year-old said he had had "no contact" with Mercedes so far. He is under consideration by the former world champions for Hamilton's seat next year, despite his fractious history with the German manufacturer when he was team-mates with Hamilton at McLaren-Mercedes in 2007.
Mercedes are also known to be thinking about promoting Italian rising star Andrea Kimi Antonelli, who is making his debut in Formula 2 this year and is widely considered the next potential megastar.
Asked about his future, Alonso said: "I am aware of my situation, which is unique.
"There are only three world champions on the grid, and fast world champions, because in the past maybe there were some champions who were maybe not so committed to be fast. And I am probably the only one available for 2025. So I am in a good position.
"But at the same time, when I make the decision whether I want to keep racing in the future, the first and only talk I will have in the beginning will be with Aston Martin. That will be my only priority.
"But if we cannot reach an agreement and I want to commit to race in F1, I know I have a privileged position, I am probably attractive to other teams, the performance they saw last year, the commitment."
Although Alonso is 43 this summer, he said he believed he could continue to race in F1 for several more years as long as he was motivated, and that he was performing better in fitness tests this winter than ever before, having taking into his team a nutritionist.
But he is also wary of the fact this is the longest season in F1 history with 24 races.
The two-time champion, who has already competed in 20 seasons, said: "Maybe I would have said 41 or 42 before. Now I can think maybe I can race for a few more years. So I would say if you are motivated and want to commit, you can drive until 48 or 49 or maybe even 50.
"But at the same time, you have to give up everything in life. F1 needs total dedication - I gave my life for this.
"I am happy with that and I can keep going for a few more years but I don't know if I will be racing until 50 with such a demanding calendar as that - not for the abilities but because there are other things in life I am curious (about)."
Alonso finished fourth in the drivers' championship last season, despite a mid-season slump by Aston Martin after a highly impressive start to the season which transformed them from midfielders into front-runners.
Technical director Dan Fallows described the new AMR24 as "essentially a strong evolution of last year's car".
He said it featured a new nose and front wing, revised bodywork and some secrets under the skin that would not be visible at Monday's launch.
Alonso predicted the field would be "very tight" this season and said the team had worked on last year's weaknesses, which included straight-line speed and downforce in high-speed corners.
Fallows and Alonso added they had learned from losing their direction on development mid-season.
"Some of the weaknesses and inconsistencies we saw last year from track to track, we tried to tackle all of those," Alonso said. "I am happy with the intent of all the changes. Let's see on track."
The car will run for the first time at Silverstone this week before pre-season testing in Bahrain from 21-23 February. The seasons starts in the Gulf state a week later, from 1-3 March.