The legend's brilliant career came to an end last week after Spain were eliminated in the Davis Cup Finals and his former coach is thrilled that he was able to remain himself en route to winning 22 Grand Slam titles.
Toni told ATP Tennis: "I feel very happy about everything that he’s achieved, obviously on court because of everything he won. But, above all, the most notable thing, which really pleases me as a relative, is seeing how a boy who had a dream of being a great tennis player did everything possible without losing his way.
"He always kept his feet on the ground. Staying competitive within the limits of correctness.
"That’s definitely what has pleased me the most.
"I’ve loved seeing how much people have appreciated that."
Nadal's playing time has been limited in recent years due to injury and Toni was aware that his nephew was planning to hang up his racquet.
He added: "A few months ago Rafael told me that he was thinking about retiring. He wanted to do it in Malaga during the Davis Cup.
"It was something that was more or less expected. We knew that the decision would come sooner or later. I found out a few months ago because Rafael came to tell me."
Nadal's achievements include a record-breaking 14 titles at the French Open and his uncle believes that the ace has left an indelible mark on the sport.
Toni said: "He can go with his head held high.
"After everything he achieved, having been there for many years, he has gained the immense respect of most people.
"He has left a good image at all the tournaments he participated in."
Nadal is now setting his eyes on a new career and Toni believes he will "throw himself" at whatever he chooses to do next with the "same passion as he did any tennis match".
He said: "I think my nephew will approach his new life with complete normalcy ...
"Retirement is a difficult time, but I don’t think it will be very difficult to focus on the rest of his life doing other things."