Nadal skipped the Australian Open in January with a muscle problem, and the 22-times Grand Slam champion had raised doubts about his fitness for the year's second major with lingering issues in Barcelona, Madrid and Rome.
"I'm feeling better. That's the truth. Not because I'm here," Nadal added, appearing more cheerful than he has in recent months.
"Probably because we did things to try to feel better and we have been working without a stop to keep going with the process, to try to arrive here in a proper way."
Nadal turned his attention to Monday's clash with Zverev, a rematch of the 2022 semi-final when the German retired after an ankle injury.
"It's a super-tough first round. Maybe I go there and I repeat the disaster of Rome. It's a possibility. I don't want to hide that," Nadal said, referring to a second-round defeat by Hubert Hurkacz in the Italian capital this month.
"But in my mind is something different, play much better and give myself a chance to be competitive... I didn't play this level of opponents, being competitive since a super-long time.
"So all these questions I understand that you're making to me I'm asking to myself too. But the answer is going to be on Monday, no? That's it.
"The rest of the things are just talking and talking, and in the end don't matter. It's about my feelings and my feelings are better. I want to enjoy that match."
Published 25 May 2024, 14:40 IST