Navas stayed on the pitch in the first period of the La Liga contest despite making contact on Betis midfielder Darko Brasanac in what was a last-man challenge from the Costa Rican international.
Betis ultimately suffered a 2-1 defeat to Los Blancos, and Ceballos has claimed that the match referee 'was not strong enough' to produce a red card for the home side.
"[Mateu Lahoz] knows there was contact and he admits it but not enough to call it," Ceballos told Marca. "He lacked a little bit of bravery to leave Madrid with a man less in the 20th minute."
The defeat was Betis's 13th in the league this season and left them down in 14th position in the table.