The Manchester City manager was furious that Cardiff’s Joe Bennett got only a yellow card for scything down the German winger just before half-time.
And he fears that City’s growing injury list could be his biggest obstacle to his champions elect and Carabao Cup finalists chasing a historic four trophies.
“I have said many times that the only thing referees have to do is protect players,” said Guardiola.
“This is all they have to do and it has not happened.
“I fear my players will sustain an injury, not just my players but all players.
“Please, for football in general, protect them. They are the artists, we are here for them, you are here for them, the supporters are here for them.
“Sane will be out for a while, I don’t know if it is for weeks or months, we will find out tomorrow.”