Kyrgios added that he had been in communication with Tennis Australia chief executive Craig Tiley and United Cup tournament director Stephen Farrow about his injury.
Medvedev squandered a two-set lead against Nadal in their previous meeting in the Melbourne final in January, allowing the Spaniard to clinch his 21st Grand Slam title.
World number one Naomi Osaka will "probably" defend her US Open title, even if it means defying her doctor's orders.
Novak Djokovic and Rafael Nadal won on Saturday to set up an Italian Open final meeting
Venus Williams also went the distance before claiming a 2-6, 6-3, 6-3 victory over Croatia's Donna Vekic.
World Number one Simona Halep and Japan's Naomi Osaka are among the players nominated for the Women's Tennis Association (WTA) Player of the Year award.
It will mark the first Grand Slam final to be contested by two teenagers since Serena Williams and Martina Hingis met in the 1999 US Open title clash.
IMAGES from Day 5 of the Wimbledon Championships at All England Lawn Tennis and Croquet Club on Friday.
Novak Djokovic advanced to a record-extending 10th Australian Open final with an emphatic win over American Tommy Paul.
Karolina Pliskova overcame a slow start before beating Garbie Muguruza 4-6, 6-2, 7-6 (6) in her opening match at the WTA Finals. In a contest between two former No. 1-ranked players, the third-seeded Pliskova struggled early adjusting to the nearly 5,000-feet altitude of Guadalajara, Mexico's second largest city on Wednesday.
Serbian Dusan Lajovic beat Andy Murray at the Miami Open on Wednesday, sending the Briton packing in the first round with his first hardcourt win of the season.
Carlos Alcaraz downed Felix Auger-Aliassime 6-4, 6-4 to book an Indian Wells semi-final place
A round-up of tennis matches played on Tuesday.
The Croatian was one of the hottest properties in tennis as a teenager before the personal turmoil of her upbringing caught up with her and she was forced to start all over again in 2008.
Russia's Anastasia Pavlyuchenkova stands on the threshold of finally delivering the title long predicted
Big-serving Canadian Milos Raonic fired 19 aces to topple Sam Querrey 6-4, 6-4 and set up a second-round clash with either Dan Evans or Russian 10th seed Andrey Rublev.
It was the Russian's first competitive match since she withdrew from the St Petersburg Open in January.
Inspired Garcia goes from Cincinnati qualifier to champion
Petra Kvitova overcame a sluggish start and 10 double faults to beat Madison Keys 6-7(6), 6-4, 6-3 on Saturday and advance to the final of the Cincinnati Open, where she will face Caroline Garcia, the first qualifier to reach the final of a WTA 1000 tournament.
Novak Djokovic, Rafael Nadal and Johanna Konta progressed to the Italian Open semi-finals on Friday, but Roger Federer and Naomi Osaka were forced to withdraw with injury problems. World number one Osaka pulled out of her quarter-final meeting with Kiki Bertens due to a thumb injury before 37-year-old Federer announced his withdrawal because of a problem to his right leg.
The Russian five-times Grand Slam champion struggled for rhythm initially on the low-bouncing grasscourt at the Mallorca Open but picked up the pace to beat Viktoria Kuzmova 7-6(8), 6-0.
Zverev's serve played a big role in the victory, his third of the year, as the World No 3 won all but two of his first-serve points in the final, which lasted 74 minutes.
Next up for the 35-year-old will be another American in 39th-ranked Tommy Paul with a potential semi-final clash against top-seeded Russian Daniil Medvedev, who he defeated in the Australian Open final from a two-sets deficit.
Persistent drizzle and a chill wind sweeping the almost-empty Roland Garros grounds.
Venus Williams accused Wimbledon officials of discriminating against its women champions and wants "equality" when it comes to scheduling matches on its two biggest showcourts.
Images from Day 1 of the 2023 Australian Open at Melbourne Park on Monday.
A round-up of all tennis action on Friday.
Novak Djokovic wore down Lucas Pouille after an even first set, dispatching the Frenchman 7-6(2), 6-1 in a Cincinnati Masters quarter-final in Ohio on Friday.
Muguruza wins all-Spanish clash with Badosa at WTA Finals
Djokovic, the ninth seed, was originally scheduled to play Australian Open semi-finalist Chung Hyeon but the 22-year-old South Korean withdrew with a back injury about an hour before the match was due to start.
Frenchman Benoit lost his temper in the third game of the second set when top seed Tsitsipas halted the match to attend to a broken shoe lace.
Maria Sharapova's mix of grit and power were enough to see off American teenager Sofia Kenin 7-5, 6-2 in the third round of the US Open on Friday.
Images from Day 5 of the 2023 Australian Open at Melbourne Park on Friday.
Top seed Novak Djokovic beat Canadian Felix Auger-Aliassime 7-5, 7-6(1) to reach the semi-finals of the Italian Open on Friday and move within one win of 1,000 career victories.
Nadal had a solid start, but the 35-year-old struggled physically towards the end of the contest
Alexander Zverev got the better of older brother Mischa at the Citi Open in Washington on Thursday, winning their first meeting at an ATP Tour event 6-3, 7-5.
Australian Nick Kyrgios produced another extraordinary performance to demolish compatriot Alex de Minaur 6-2, 6-3 at the Canadian Masters on Thursday, a day after stunning world number one Daniil Medvedev.
IMAGES from the matches played at the Miami Open on Thursday
Summary of sports events and persons who made news on Thursday
Images from Day 5 of the Australian Open in Melbourne on Friday.
