The 21-time grand slam champion missed a large part of last season with the injury and says he is still learning to live and play through the pain.
The Spaniard appeared to struggle badly toward the end of his last game on Thursday as he fell to defeat against Denis Shapovalov at the Italian Open.
"I am a player living with an injury -- it is nothing new. It's something that is there," Nadal told reporters after the match.
"Unfortunately, my day-by-day is difficult, honestly. Even like this, I am trying hard... it can be frustrating that a lot of days I can't practice the proper way."
In early May, Nadal told the media after his dramatic round-of-16 win against David Goffin at the Madrid Open that he had a "chronic injury which has no treatment."
He went on to say, "When I play, sometimes my foot pains me. If you see me every single day, you wouldn't be worried. I always have pain in my foot, especially after playing a three-hour match or a long training. I end up walking a little bit badly.
"But I have a chronic injury which has no treatment. That's part of my life, and that's the downside of not being able to finish the match earlier. In the short term, I think I am fine, physically speaking, but also, speaking about my feet, it has to adapt to competition."
Training through 'pain'
The 35-year-old staged a remarkable comeback from last year's long injury lay-off to win the Australian Open in January but he says the issue with his foot has been "tough."
He confirmed he would be bringing his doctor along for the French Open in order to manage the injury as best as possible.
"First thing that I need to do is to not have pain to practice," added Nadal, who is only just returning from a rib injury suffered at Indian Wells in March.
"It's true that during the French Open, Roland Garros, I am going to have my doctor there with me. That sometimes helps because you can do things.
"In the positive days and in the negative days, you need to stay and to value all the things that happened to me in a positive way."
Roland Garros is set to run between May 22 and June 5.