The 22-time Grand Slam champion will make his return from a near year-long injury absence at the Australian Open warm-up event in Brisbane next month.
The 37-year-old had previously suggested he would hang up his racquet at the end of 2024.
"There's every chance that it's going to be my last year and I'm going to enjoy the tournaments in that way," Nadal said in a video posted on his social media accounts.
"I don't want to announce it because in the end I don't know what can happen and I have to give myself the opportunity not to say one thing as then I'll be a slave to what I said.
"I think it's going to be like that but I can't be 100 percent sure because in the end I've worked a lot to come back to compete and if suddenly things and my physique allow me to continue and enjoy what I do, why am I going to set a deadline?
"I think it makes no sense."
Nadal was named on the entry list for the Australian Open earlier on Thursday ahead of the start of the first Grand Slam tournament of the year on January 14.
The Spaniard has not played since a second-round loss to American MacKenzie McDonald at Melbourne Park 11 months ago.
He twice needed surgery after struggling with a hip injury and has slipped to 664th in the world rankings while sidelined.
