Two Sydney Trains workers have been stood down after video emerged showing them knocking out a visually impaired passenger by stamping on his head - because he was allegedly drunk and aggressive.

The station duty manager at Blacktown and a security contractor were reprimanded as Sydney Trains investigates the ugly incident - captured on mobile phones by concerned train users.

The visually impaired man, seen with his guide dog by his side, was allegedly fighting with a security worker on the platform after he was removed from the train last night.

But footage shows the station manager restrain him before a shirtless staff member stomps on the man's head - knocking him out cold.

Speaking today, spokesman for Sydney Trains Tony Eid condemned the actions of staff but confirmed that one of them did require a trip to hospital after allegedly being bitten.

"That action is unacceptable,” Mr Eid said.

“That action is something that we do not a condone and certainly we don't train our people to take that sort of action.

"We did have a station staff member who was bitten, we've taken him to hospital as a precautionary measure because he did break skin."

Despite the shocking vision police said that they would not be taking any further action at this time, because no official complaint has been lodged.