The German international appeared to catch West Ham defender Matthew Upson in the face during Stoke’s 2-1 victory on Saturday.
“I saw the incident. Matthew is okay now, he had a few stitches,” said Zola.
“Looking at the video after the match obviously it was a sending-off. I can only assume the referee didn’t see it.
“I haven’t spoken to the referee about it. I don’t think I need to talk to him.
“It is down to the authorities to decide (whether further action is required) – it won’t change the story for me.”
