Stan Wawrinka has won three grand slam titles and appeared at the Mubadala World Tennis Championship on four occasions. Aurelien Meunier / Getty Images
Stan Wawrinka has won three grand slam titles and appeared at the Mubadala World Tennis Championship on four occasions. Aurelien Meunier / Getty Images

Anderson and Rublev replace Wawrinka and Raonic at Mubadala World Tennis Championship