Roger Federer, of Switzerland, tosses the ball on a serve to Radu Albot, of Moldova, during the Miami Open tennis tournament Saturday, March 23, 2019, in Miami Gardens, Fla. (AP Photo/Lynne Sladky)

Roger Federer, of Switzerland, returns to Radu Albot, of Moldova, during the Miami Open tennis tournament, Saturday, March 23, 2019, in Miami Gardens, Fla. (AP Photo/Lynne Sladky)