From the first ball Toni Nadal threw towards his three-year-old nephew, he could see there was something different about the kid lining up a shot on the other side of the court.
Once a top Spanish amateur player who competed in the national championships, the coach had hundreds of children come under his watchful eye at Manacor Tennis Club on his home island of Mallorca.
"When I hit the ball to Rafael, he went towards it. He didn't wait for the ball to arrive to him," Toni tells BBC Sport.
"Normally, when I sent a ball to a small kid, he stood and waited until the ball arrived at him.