"I felt some pain in my knee during today's training, and I have experienced this with a previous injury. I consulted with my medical team, and we have decided that I cannot risk anything before the start of the clay season. I need to be 100 percent ready to play matches – especially in a fast format like UTS."
"I will therefore spend the next few days recovering, and therefore I am withdrawing from UTS in Nîmes. I apologize to the French fans, because I was looking forward to it", says Rune in a press release.
Australian Alexei Popyrin will take over Rune's place in the show tournament, which is not related to the ATP Tour.
Andrey Rublev, Alex de Minaur, Casper Ruud, Tomas Machac, Ben Shelton, Ugo Humbert and Gael Monfils are the other participants in this weekend's show tournament.
Rune is expected to embark on the clay season when the ATP 1000 tournament in Monte Carlo starts on Monday.