The 65-year-old, who has been out of work since being sacked by United last May, told Spanish radio station Cadena Ser in the early hours of Wednesday morning that he had rejected an offer to coach struggling Spanish club Valencia last month.
Dutch newspaper De Telegraaf said on Monday Van Gaal had decided to call time on his coaching career, with the sudden death of his son-in-law influencing his decision.
"I've not retired," he told Cadena Ser. "I'm on a sabbatical year and then I'll decide if I do or not. There's a big possibility of me retiring but it's not definitive.
"In Holland the press write whatever they want. Like in Spain, they pay attention to other things."
Van Gaal, who lead Ajax Amsterdam to the Champions League title in 1995 and won league titles with Barcelona, AZ Alkmaar and Bayern Munich, said his return would depend on which team came in for him.
"Whether I continue or not will also depend on the offers I get. I've coached many clubs and I think it's very difficult to improve on that level of clubs," he added.
"It's not true that I've retired, not at this moment, but I'll decide at the end of my sabbatical, next June or July."
Van Gaal had told Dutch media he had turned down a lucrative offer to coach in China after the death of his son-in-law.
"I could have gone there (China), but I'm still here," Van Gaal was quoted as saying. "So much has happened in my family that I have been forced to look at things differently." "I had said (after leaving Manchester United) that I would stop but I changed that into a sabbatical, but now I believe that I will not return to coaching."
Asked if he did not have any remaining ambitions, van Gaal said: "No, actually not. I have got everything in my life. I find it boring to mention it all but look at the countries where I have worked and the level of the clubs that I have coached, and there is nothing that remains. "I actually wanted to stop after the World Cup (in Brazil in 2014) but then the opportunity in England came up. And that was a fantastic country that is now also on my CV."
(Reporting by Mark Gleeson in Port Gentil, additional reporting by Richard Martin; Editing by Amlan Chakraborty/Peter Rutherford)
