Fernando Alonso said he is "attractive" to other Formula One teams but denied any contact with Mercedes after Lewis Hamilton announced he was quitting to drive for Ferrari in 2025.
Hamilton's departure at the end of this season will create a vacancy alongside George Russell, while Max Verstappen's Red Bull team are also due to have a seat available, with Sergio Perez's contract expiring at the end of the season.
The 42-year-old's two-season deal with Aston Martin is up for renewal in 2025, but the Spaniard believes he is capable of competing in F1 until he is 50.
Speaking ahead of Monday's launch of the team's AMR24 car, Alonso, who won back-to-back world championships with Renault in 2004 and 2005, said: "I am aware of my situation, which is very unique.
"There are only three world champions on the grid and I am the only one available for 2025, so I am in a good position.
"On a move to Mercedes, there has been nothing at all. I know the driver market has started earlier this year, but this will not affect me in terms of preparing for the season.
"If I want to keep racing beyond this year, the first and only talk at the beginning will be Aston Martin. I trust this project and that will be my first priority.
"But if we cannot reach an agreement I know that I am attractive to other teams. I will not stay in Formula One just to have fun. I am not that kind of person and not that kind of driver. Let's see what the options are."
Commenting on Hamilton's move to Ferrari, Alonso, who drove for the Italian team between 2010 and 2014, added: "It was a surprise, I will not lie, not because of the change itself but from the outside it seemed like he was very linked to Mercedes and very loyal to Mercedes.
"Ferrari is a special team but it is more special when you win. Maybe Lewis can bring that extra fight for the championship because the car is there."
Alonso finished fourth in last year's drivers' championship as Aston Martin shot up the grid from also-rans to frontrunners.
The Spaniard will this season become the first man to take part in 400 Grands Prix and the evergreen driver raised the prospect of competing deep into his forties.
"A few years ago I would say 41 or 42 is the limit, but after last year I saw I was motivated, performing well, and I was thinking I could race a few more years," he said.
"Now, this winter, I have exceeded expectations in terms of the physical tests, so if I am motivated and ready to commit, I can race until 48, 49 or maybe even 50."