Jenson Button is not ruling out a full-time return to Formula 1.
Last year, despite the F1 veteran inking a new two-year contract with McLaren, the Briton said that the 2016 Abu Dhabi race would be his last in F1.
However, he is making a one-off return in Monaco next weekend to replace Fernando Alonso, who is doing the Indy 500 and now, the 37-year-old said that he might come back full time in 2018.
"I can't rule it out," Button is quoted as saying by The Sun.
"I have a contract with the team to race next year so I would definitely not rule anything out," he added.
Alonso's contract runs out at the end of the year.
Button, however, said he would not actively push to do more races this year, as he went into 2017 planning to have "a break".
"I had so many options to race this year it is hilarious," he revealed.
"That even went into this year with two different teams asking me to race. I have no interest in doing that."
As for his chances in Monaco, Button was criticised recently for not doing the Bahrain test to prepare, and has now admitted: "I don't know what is going to happen.
"I don't know if I am going to jump in the car that it feels so different that I won't be competitive."
Button's F1 career began with Williams in 2000.