"He was a bit groggy but didn't lose consciousness. We dealt with him and later he seemed fine - he was laughing and joking later and set off home," said Millers physio Denis Circuit in the Star.
"But we had warned him about delayed concussion and what signs to be aware of."
After falling ill later the right back was admitted to hospital for treatment.
Circuit added: "He had a CT scan to check there was no bleeding on the brain - there wasn't, it was all clear and he was kept in overnight for observation and discharged."