The issue arose when outspoken Srdjan Djokovic, father of world No 1 Novak Djokovic, told Serbian media that his son and Nadal no longer get along.
The high-profile players have met 35 times, with Nadal boasting a 20-15 winning record. But he has struggled in recent years against the Serb, with Djokovic winning eight of their last 12 meetings, including a seven-match streak from 2011 to 2012.
The elder Djokovic charged: "Rafael Nadal was Novak's best friend while he (Nadal) was winning. When things changed, they were no longer friends."
Nadal told media on his home island of Mallorca that he and Novak get along fine and advised Srdjan: "If he wants to know how I get along with Nole, he should ask his son. My relationship with Novak has always been very good and it still is.
"I've lost lots of matches against him and vice versa, but we've never had a problem. People are entitled to their opinions. It's not my place to respond to anyone, especially without having heard or read these comments."
The elder Djokovic also unloaded on Roger Federer.
"Federer may be even the best tennis player in history, but as a person is totally the opposite," he said. "Novak attacked in the Davis Cup in Geneva, realised that is his heir and tried everything to discredit him."
Nadal also dropped a big hint that he is hoping to play both next week's Masters 1000 in Montreal as well as the week after in Cincinnati. Speculation in the Spanish sporting press by the Marca tabloid had suggested that the No 4 would play in Montreal and rest his knees during the Cincinnati week to be fit for the US Open starting August 26.