An under-the-weather Federer lost 6-3, 6-3 to the 17-year-old, who then took a two-set lead against Federer in the final a year later before losing in five. They have played another 31 times since then, with Nadal holding a 23-10 overall edge.
Federer recalls being impressed with what he saw in their third-round encounter ten years ago.
"I came off sunstroke in Indian Wells after beating [Tim] Henman in the finals. I was in bed three or four days, and then came here," he told reporters in Miami. "I beat [Nikolay] Davydenko somehow 7-5 in the third, then started feeling better and played Rafa, who was a new guy on the tour.
"I remember it was one of those matches...never really got into the match. Still maybe a bit tired but he played great."
Nadal's victory received only limited attention back then, but provided a sign of the challenge he would soon pose for the then-world No. 1.
"I was impressed with what I saw. Don't remember going into the match what the buzz was around him...but anyway, that was clearly for him a big arrival on the scene, especially on the hard courts as well. I was world No. 1 at the time as well...I think everybody thought he was just a clay-courter, and he proved he was probably going to be more than just that.
"Went on to have this great career many expected him to have," remarked Federer.