Stan Wawrinka has slammed the ATP Davis Cup format and Gerard Piqué as the Group Stages prepare to get underway.

In 2019, the International Tennis Federation (ITF) signed a 25-year deal with Kosmos, founded and led by Spanish former footballer Gerard Piqué, forming a partnership that cost $3 billion.

As part of the new deal, big changes were made to the format of the Davis Cup, with the World Group taking place in one week at one location. Moreover, the World Group is now played as one single tournament, named the Davis Cup Finals.

Some players were critical of the format change with many predicting that it would not be financially sustainable. Indeed, in January of this year, the deal between the ITF and Kosmos collapsed.

At the time, Piqué said that he believed Kosmos had helped the Davis Cup by bringing in more fans.

"We believe that what we have done with the Davis Cup is a resounding success," he said, "We arrived with a competition which was in decline, which was at its lowest. And in terms of sport, economics and viewership, we have above all reformed the tournament."

However, three-time Grand Slam champion Wawrinka did not seem to agree with Piqué. The Swiss player is currently competing for his country's team in the Davis Cup Finals Group Stage. Switzerland are in Group B along with France, Australia and Great Britain, who are all playing in Manchester from September 12-17.

On the social media platform X, formerly known as Twitter, Wawrinka shared a video of an almost empty stadium for France v Switzerland, with the caption:

"Thank you @3gerardpique@ITFTennis!" followed by an angry emoji and an emoji of a person with their head in their hands.

"@DavisCup France vs Switzerland in Manchester lol," he continued.