The Serb talked about his decision to change coaches with the media at Monte-Carlo.
The World No.1 is in the same half as Alcaraz and defending champion Rublev.
"Either you're going 100 percent or it's better not to participate," Toni Nadal said of Rafa Nadal's Roland Garros hopes.
The Spaniard posted the news on social media, saying he's body is not ready for competition.
Andy Murray's recovery from torn ankle ligaments has just begun, but he has a comeback target in sight.
The USTA aims to increase the country’s tennis-playing population to 35 million total players, or 10% of the U.S. population by 2035.
The Wuhan Open, last staged in 2019, is set to return in October, Chinese media reports.