Novak Djokovic is through to the semi-finals of Wimbledon after Alex de Minaur withdrew from their last-eight tie because of a hip injury.

The Australian ninth seed was scheduled to take on 24-time Grand Slam champion Djokovic in Wednesday's second match on Centre Court.

Djokovic, 37, is handed a walkover and will face Lorenzo Musetti on Friday as he bids to reach the final for the sixth time in seven years.

"I am devastated to pull out due to a hip injury," De Minaur said.

"I felt a loud crack during the last three points of my match against [Arthur] Fils.

"[I] got a scan yesterday and it confirmed that this was the injury and with high risk of making it worse if I was to step on court."

De Minaur defeated Frenchman Fils in four sets on Monday to reach his first quarter-final at Wimbledon.

The 25-year-old said the recovery period was between three and six weeks.

"I have been struggling to sleep the last couple of days. I feel it [when] walking," De Minaur said.

"Just hoping that I would wake up and feel it a little bit less or feel it to a point where I can at least go on court.

"But, again, I think it's almost disrespectful for me to not go on the court close to 100% against someone like Novak because there's no point of me going out there if I'm not going out there to try and win."

His withdrawal helps Djokovic in his bid to win an eighth title at Wimbledon and move level with Roger Federer.

He has now moved into a 13th Wimbledon semi-final - a joint Open era record with Federer.

Djokovic has looked in excellent form at SW19, despite undergoing knee surgery just three weeks before the grass-court Grand Slam.

He made light work of 15th seed Holger Rune in the quarter-finals.

In his on-court interview afterwards, he accused fans of disrespecting him, saying they used a Rune chant as "an excuse to boo".

Wimbledon organisers have filled the slot on Centre Court with a second-round mixed doubles match featuring British duo Joe Salisbury and Heather Watson, who take on Jan Zielinski of Poland and Taiwan's Hsieh Su-wei.

That will be followed by a women's invitational doubles match, with Australia's Ashleigh Barty and Casey Dellacqua playing Germany's Andrea Petkovic and Magdalena Rybarikova of Slovakia.