Rafael Nadal says he does not think his uncle and former coach Toni could ever wish him to lose - despite now guiding his next opponent at the French Open.
Nadal, 35, plays Canadian ninth seed Felix Auger-Aliassime in the fourth round at Roland Garros on Sunday at around 15:00 BST.
Auger-Aliassime says he thinks Toni Nadal will watch the Court Philippe Chatrier match from a "neutral" place.
"I want the best for him and he wants the best for me," said Rafael Nadal.
"I don't think he will be able to want me to lose, without a doubt. But he's a professional and he's with another player."
Nadal, seeded fifth after missing a chunk of the season with a rib injury but seeking a record-extending 14th Roland Garros title, could set up a quarter-final meeting with defending champion Novak Djokovic.
Serbia's Djokovic, 34, faces his biggest test so far when he faces 15th seed Diego Schwartzman at around 12:00 BST on Court Suzanne Lenglen.
'He's not only an uncle - he's more than that'
Nadal was coached by his uncle Toni, the younger brother of his dad Sebastian, from the age of three.
Under his tutelage, Nadal won 16 of his record 21 Grand Slam men's titles.
Toni retired from Nadal's team in 2017 and concentrated on running his nephew's academy close to the Mallorcan village of Manacor where the family all still lives.
But the 61-year-old made a surprise return to the tour on a part-time basis last year, working with Auger-Aliassime at the Grand Slams and other leading events.
In an interview with Spanish media last year, Toni Nadal said he would not be able to sit in Auger-Aliassime's box if he played his nephew.
"I don't know what's going to happen, if he's going to stay in the box or not, but I don't care. I have zero problem with that," said Rafael Nadal, who has not dropped a set in his opening three matches.
"We are family more than anything else. Not only family; we are a family that we stay together all the time.
"He's not only an uncle. He's more than that."
Auger-Aliassime, who had never won a main-draw match at Roland Garros until this year, also played down the significance of Toni's potential absence from his team during Sunday's match.
"It was black and white from the first time we started working together - we knew it was a possibility that eventually I would play Rafa when I'm working with Toni," he said.
"I don't think we are going to talk much about the match.
"I know Rafa, I've seen him play, I know what he does well. We all know."