Matsuda was involved in an incident with two GT300 cars exiting the high-speed 130R in the closing stages of June's third round of the season, the impact with the barriers and catch fencing destroying his NISMO-run Nissan Z.
The two-time GT500 champion had to be airlifted to hospital, but Nissan reported he had avoided any significant injuries. Three days later, he was transferred from intensive care to a general ward to continue his recovery.
Matsuda was finally released from hospital in mid-July, six weeks on from the crash, and was deemed fit enough to take up his regular seat in the #23 Nissan alongside team-mate Ronnie Quintarelli this weekend at Fuji.
Speaking to selected media, including Motorsport.com's Japanese edition, at Fuji on Friday, Matsuda revealed he had been unable to walk initially after suffering a crack in his right ankle and damage to the muscles in his thighs.
"I remember everything [about the accident]," he said. "But the impact was so massive, I was in so much pain that I couldn’t get out of the car under my own power. I was just thinking that I hope my leg isn’t broken.
"A lot of thoughts were going through my head, such as being worried about whether I would be able to make a comeback.
"The muscles at the base of my thighs on both legs were damaged. There was also a small crack in the bone of my right ankle, so that had to be secured with a cast.
"I wasn’t able to walk. I was doing training and rehabilitation that you can do even while in a wheelchair. From there, I steadily started to practice walking and eventually I was able to walk again.
"My upper body was basically fine, so I was able to train [my upper body] from mid-June. I started training my legs on July 5, and from that point on I was able to increase my strength fairly quickly."
Matsuda said that the plan was to target a return to racing for this weekend's Fuji round from an early stage, but admits that he isn't yet back at 100 percent fitness.
"When I moved from Yokkaichi Medical Centre to Suzuka Kaisei Hospital, we discussed what would be best to allow me to get back to racing in August," he explained.
"Regarding the torn muscles, we established how long it would take for the muscles to repair themselves, and until that time I was careful not to move them.
"That period was long, so I was getting impatient, but I followed the plan that the doctors had put together, the rehabilitation went well and finally it was decided I could participate this weekend.
"It would be a lie to say I’m at 100 percent fitness. I would say I am at 70 or 80 percent. My left leg [braking leg] is almost back to 100 percent. My right leg is more than 50 percent.
"Even when I wasn’t able to use my legs, I was able to train using a hand cycle, so I think I should be ok in terms of stamina."
Matsuda and Quintarelli sit third in the GT500 standings heading to Fuji despite the Suzuka crash, having won the opening race of the season at Okayama and finishing seventh in May's second round at Fuji.
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