Switzerland's Roger Federer plays a return to Germany's Dominik Koepfer during their third round match on day 7, of the French Open tennis tournament at Roland Garros in Paris, France, Saturday, June 5, 2021. (AP Photo/Thibault Camus)

Switzerland's Roger Federer, left on court, plays a return to Germany's Dominik Koepfer during their third round match on day 7, of the French Open tennis tournament at Roland Garros in Paris, France, Saturday, June 5, 2021. (AP Photo/Thibault Camus)

Switzerland's Roger Federer plays a return to Germany's Dominik Koepfer during their third round match on day 7, of the French Open tennis tournament at Roland Garros in Paris, France, Saturday, June 5, 2021. (AP Photo/Thibault Camus)

Germany's Dominik Koepfer p adjusts his hat as he play against Switzerland's Roger Federer during their third round match on day 7, of the French Open tennis tournament at Roland Garros in Paris, France, Saturday, June 5, 2021. (AP Photo/Thibault Camus)

Germany's Dominik Koepfer plays a return to Switzerland's Roger Federer during their third round match on day 7, of the French Open tennis tournament at Roland Garros in Paris, France, Saturday, June 5, 2021. (AP Photo/Thibault Camus)

Switzerland's Roger Federer celebrates after defeating Germany's Dominik Koepfer in their third round match on day 7, of the French Open tennis tournament at Roland Garros in Paris, France, Saturday, June 5, 2021. (AP Photo/Thibault Camus)