According to the sister of
Holger Rune, the Dane replaced a poster of Nadal with one of Federer after he lost a match dressed as the Spaniard when he was younger.
Rune was a big fan of both Nadal and Federer growing up and had a habit of trying to dress as them on a tennis court. He lost a match in the final and was furious after losing it not willing to accept the trophy. When he returned home, Rune replaced Nadal with Federer as well:
“He went bananas because he wanted to win. And we tried to calm him down and say, ‘It's okay and go take your [runner-up] trophy.’ He didn't want to accept the trophy. So we had to take it home in the back. When he came to his room he said, ‘Take down Rafa.’ At that time, Rafa was No. 2 and Roger was No. 1. And he said, ‘Put up, Roger’."
His mother confirmed the story explaining that finishing second was the first thing for him:
“He said, ‘I never want to be No. 2, it's the worst."
His sister further added:
“In Denmark, there is not a rich culture of elite tennis. They were not whisked away to a world-class academy with the best juniors in the world. Some of their most memorable moments as kids were playing against one another."