Just after 10.30pm, a white van pulled up in front of his house.

Inside, by the dim yellow cabin light, Mr Johnson, 88, saw two young girls left alone as the male driver wandered off down the street.

Concerned that the girls had been left unattended, the former shipwright went down to inspect the van.

The driver returned and without warning, allegedly bashed Mr Johnson brutally, inflicting cuts and bruising to his face and numerous fractures to his pelvis.

Mr Johnson, affectionately known as "Slim" by his neighbours, was left with a blackened eye socket on Green Point Road, as the van sped away with the girls still inside.

Paramedics and police soon arrived to take the Cronulla Sharks fan to Sutherland Hospital, where he remained over the weekend.

Mr Johnson's grandson Dale Ross described his grandfather as the kind of man who wouldn't hesitate to offer help to a stranger in trouble.

"He's from a different era to us, so the idea of a car stopping out the front, possibly someone in distress, naturally he would have wanted to help," Mr Ross said.

"He's the type of person who would ... ask if they wanted to use the phone, wait inside in the warmth if it was cold."

He said his grandfather had been an "active, strong and fearless" man but had become increasingly frail. In recent years he had come to require the support of a walking frame or walking stick.

"It's frustrating to think that he's not safe near his own house, doing something he thinks is normal," Mr Ross said.

He appealed to his grandfather's attacker to come forward and tell his version of events.

"Obviously there's two sides to every story," he said.

Neighbours said the news of the alleged bashing was distressing.

"You don't expect it to happen in your street," said a resident who asked not to be named. "It is disturbing. I just wish we were able to do more to help."

Another neighbour said Mr Johnson was well known throughout the community, having lived in the street for the past six decades.

"Slim always waves hello and has a chat in the street," she said.

Cronulla Sharks chief executive Lyall Gorman said that the thoughts of Mr Johnson's beloved club were with him.

"Our only wish is that he is back on his feet as soon as possible. We have extended to Eric and his family an invitation to come to our next home game and to meet some of the boys in the sheds after full-time. It's the least we can do to hopefully put a smile on the face of a long-time Sharks fan who is doing it  tough at the present time."

Police have released graphic images of Mr Johnson's injuries in a bid to get more information from possible witnesses.

Police described the man as being 183 to 185 centimetres tall, with a thin to medium build and an Australian accent.

The alleged attacker's vehicle is described as an older model white van with PVC piping attached to the roof.

Police are urging anyone with information to call Crime Stoppers on 1800 333 000.