The long-time coach of Rafael Nadal has spoken about how he looked for ways to strengthen his nephew’s character from the very beginning.

The 20-time Slam champion is renowned for his grit and determination on court, as well as his unending fight in pursuit of victory.

That kind of resolve does not come from nowhere, as his uncle Toni elaborates.

“For years I made him train in bad conditions and with balls in bad conditions,” Toni Nadal told Marca.

“Sometimes I told him that we were going to train for an hour and a half and then I would extend the training indefinitely.

“All my life I had the obsession to prepare Rafa for difficulty. [He had to] learn to strengthen his character.”

Such cultivated drive has seen Nadal claim 20 Slam titles, 13 at Roland Garros, some would argue the most difficult Slam to capture.

The Spaniard also boasts 36 career Masters 1000 titles, a joint-record with Novak Djokovic.

Nadal also sits fourth on the list of men with the most singles titles in the Open Era with 88. Only Ivan Lendl (94), Roger Federer (103) and Jimmy Connors (109) have more.

Over 20 seasons on the ATP tour, Nadal has amassed 1028 wins over 1237 matches. That amounts to a win percentage of 83.1%. At time of publication, this is second only to Djokovic, who sits a 10th of a percent higher on 83.2%.

Fellow 20-time Slam champion Federer sits fourth on 82%, just behind the legendary Bjorn Borg on 82.4%.