The world No1 won this event in 2008, and went on to win at Wimbledon in an epic final against Roger Federer. He was unable to defend either title last year because of injury, and his chronic knee problems led many to suspect he would never be the same player again.
Now, with those health issues behind him, the Spaniard is once again a formidable force. He regained the top ranking by claiming his fifth Roland Garros title last weekend, and his win against Daniel stretched his unbeaten run to 23 matches.
Nadal had hoped to play a doubles match first, and to get in more than the minimal practice which was all he managed on Tuesday. But if there was any adverse effect on his play it can only have been marginal. "I could only practice for 15 minutes yesterday, and with those conditions – raining, and with the balls too heavy," he said.
"And I was really tired, so I practiced very bad. And I really would love to have the doubles before the singles, but anyway, today during the match in singles I felt well.
"I felt I was returning well. That's the most difficult thing for me. The serve – I was serving well in Roland Garros and I did the same here, I think."
Asked if he thought he was a better player now than when he won Wimbledon, Nadal at first responded by suggesting he was not. On consideration, though, he decided he was – a conclusion which can hardly be reassuring to his forthcoming opponents.
"I don't know. You know, sometimes (it] seems like you are playing better than a few years ago, but if you have a video and you watch the match in Wimbledon against (Andy] Murray quarter-finals, against Federer the final, is difficult to be playing much better than that.
"And, you know, seems like on clay I improved a lot for these years. I think I am better player because I am more complete player. In general I am better player because I am running less than before, but that's all."