Holger Rune's mother and manager Aneke has added her voice to those criticizing the use of heavier balls on the ATP and WTA Tours, while also condemning the slower courts.

World No. 5 Rune has been dealing with a back injury throughout recent months, leading him to retire from his first-round match at the Cincinnati Open in August before withdrawing midway through the Davis Cup in September. Most recently, he crashed out of his opening match against Brandon Nakashima at the Shanghai Masters.

Meanwhile, a multitude of players have been calling out the ATP and WTA's use of heavier balls on Tour and the constant changes in balls between consecutive tournaments. Throughout this season, Stefanos Tsitsipas, Daniil Medvedev, Ons Jabeur, and Paula Badosa have been among the many names to add to this criticism.

"There is broad agreement that the balls are not what they used to be. They very quickly become heavy and slow and harder to play with," Aneke said as per Ekstra Bladet.

"At the same time, the surfaces have become slower, and then it suddenly becomes a cocktail that gives long, grueling duels with a heavy ball," she continued, before adding that the decision to make the balls and court more challenging didn't make sense when other aspects of the sport, such as shoes and rackets, were being optimized.

"When you optimize shoes, rackets, etc. to minimize stress, it seems bizarre that you downgrade the quality of the ball," she added.

The mother of the Danish tennis star also stressed that the fact that so many top players had experienced injuries this year highlighted that there was a serious problem, especially as there is no off-season in tennis.

"When several players, as I understand it, are out with wrist and shoulder injuries, it is clear that you will have to look at the quality of the balls. It is unnecessary wear and tear on the players, who have been used hard beforehand.

"Tennis is one of those sports where there are really no breaks other than December. So, it's a tough enough program already," she said.