Ryder's family was flying to be by their son's bedside, Newstalk ZB reported.
St John today confirmed it was alerted to an alleged assault at 12.34am on Papanui Road, Merivale.
Two ambulances were sent to the scene.
``We transported to Christchurch Hospital ED under lights and sirens one patient, a male, aged in his 20s, with very serious head injuries.''.
It was understood Ryder also suffered a collapsed lung. RNZ said it had learned Ryder was in a coma.
A witness, who only wanted to be known as Adam, told Fairfax that Ryder had his shirt ripped off his back and was on the ground as four men kicked and punched him outside the bar.
Ryder was lying in a bush ``shaking, vomiting and covered in blood'' in the McDonald's carpark.
Adam, who was drinking at the bar, said the brawl broke out behind him.
``From what I could tell it looked pretty unprovoked,'' he said.
Four men started punching Ryder in the bar's courtyard and the fight was quickly pushed out on to the street.
``Four dudes were just laying into him and absolutely smashing him on the ground. His shirt was ripped off and they were kicking him and punching him while he was down.''
Ryder managed to stand up during the attack but was quickly knocked back to the ground.
He was not sure if the men were friends of Ryder but said they ``damn knew who he was''.
Ryder's attackers were swearing at him as they beat him.
The four men ran off when police sirens were heard, he said.
Owner of Merivale McDonalds Murray Traill said he was investigating the incident and going through security footage. He said he would do everything to help police.
Staff last night did not see Ryder inside the restaurant. ``We don't believe it's happened inside our restaurant. We're really keen to find out what happened.''
Steve Holmes, general manager of Aikmans bar in Merivale, confirmed Ryder had been at the bar with Wellington Firebirds teammates last night.
He said the incident started outside the bar.
He had reviewed security camera footage and had given it to police but wouldn't say what it showed.
Nor would he say if Ryder had been drinking alcohol in the bar.
Mr Holmes wished Ryder all the best and hoped police would quickly track down his attackers.
No bouncers were on the door last night, saying it was a typical, quiet Wednesday night.
Blood could be seen on the footpath directly outside the entrance to the bar.
New Zealand Cricket tweeted ``The whole NZC team's thoughts are with @DijaRyder this morning''.
Ryder's manager Aaron Klee wrote on Twitter ``Thanks for the calls and msgs of support for Jesse. Just heading to Chch to see him.''
