Roger Federer warned that the Davis Cup should not become the "Piqué Cup" as he questioned the Barcelona star's involvement in the competition's overhaul.
The International Tennis Federation (ITF) approved a major change to the Davis Cup beginning next year, with the team tournament to be played as a week-long season finale. But Kosmos, an investment group founded by Piqué, reportedly want the event played in September, leading to a potential clash with Federer's Laver Cup.
Federer said he was yet to speak to Piqué, but warned organisers they needed to be careful with their Davis Cup changes.
"The good part of all this confusion is that everyone will have to sit around one table and listen to the other's desires," Federer said.
"The ITF, the Association of Tennis Professionals, the Laver Cup. It is true that the coming weeks may be very interesting.
"Meddle in tennis business"
"I have not spoken to Gerard Piqué yet, but I admit that it's a bit odd to see a footballer arrive and meddle in the tennis business. Be careful: the Davis Cup should not become the Piqué Cup.
"I am globally for innovations: our sport needs to think a little outside the box to innovate.
"But it's a bit like in a part of Jenga, you have to be careful not to remove the room that will bring down the whole building."