Six-time Grand Slam winner Boris Becker confirmed on Thursday he has become the coach of Denmark's Holger Rune, returning to the game after a seven-year absence that included a prison term.

Speaking with Eurosport, the 55-year-old three-time Wimbledon champion said "I am Holger Rune's coach", describing the 20-year-old Dane as "a rough diamond that needs polishing."

"It makes me a little bit proud that he chose me" Becker said.

"The contact between us has been going on for a long while. It's a great fit."

Becker has been working as a TV expert since being released from prison in London in December, having served a sentence for hiding assets from tax authorities.

He coached Novak Djokovic from 2013 to 2016, helping the Serb win six Grand Slams and 14 Masters 1000 titles.

Becker likened Rune to the 24-time Grand Slam winner, saying: "I like his emotional outbursts, I've coached a player like that before in Novak Djokovic."

The German, who told a then 16-year-old Rune on Instagram in 2020 to "not speak about your goals publicly... and go out and play to win", said he was "always interested in him because he is so committed and temperamental on the tennis court."

"He is one of the best young players in the world," Becker said, saying "my goal is to find the best Holger."

A former world junior No 1, Rune reached the quarterfinals of Wimbledon and the French Open in 2023, which saw his world ranking rise to four – the highest ever for a Danish male player.

He has however suffered a run of defeats recently, including losing in the first round of the Stockholm ATP tournament against Serbian Miomir Kecmanovic on Wednesday.