"I am well aware that I'm a very old man and it will soon be 'over and out'...but I'd like one or two more fights before it's all over," the 47-year-old heavyweight told Denmark's TV2 ahead of surgery planned for Wednesday.
"But it's not just me who decides, the family will also have something to say. I haven't discussed it with the doctors, it's not necessary."
Nielsen's last outing in the ring ended in a defeat by Evander Holyfield in May 2011 in Copenhagen in a WBF heavyweight title bout.
The Dane, who boasts a professional record of 64 wins in 67 fights, said he will know soon after his operation whether a comeback will be possible or not.
"If I'm not back on my feet after a month, it's over. But that's not how it'll be - I'll be up again after a week," Nielsen said. (Reporting by Philip O'Connor in Stockholm; Editing by Mark Meadows; email@example.com; +44 20 7542 7933; Reuters Messaging:; firstname.lastname@example.org)