New Zealand cricketer Jesse Ryder emerged from an induced coma Saturday, but faced "a big battle" ahead as he recovered from a vicious assault, his manager Aaron Klee said.

Ryder required medical assistance to keep breathing when he was rushed to hospital in a critical condition early Thursday morning.

He suffered serious head and lung injuries after being attacked as he left a bar in the South Island city of Christchurch.

Two men have been charged with assault and police said they were not looking for anyone else, although witnesses said up to four people were involved in what they believed was an unprovoked attack.

"Jesse's condition has improved to the extent that he is now out of the induced coma and off the ventilator. Jesse is awake and talking to us," Klee said.

"Naturally we are thrilled with this progress. This is only the start of the recovery process for Jesse and there is still a big battle ahead to full health, but the progress is positive."

Witnesses said Ryder was left "shaking, vomiting and covered in blood" after he was repeatedly punched and kicked.

Klee said Ryder had no recollection of the attack.

"He remembers getting a duck ... not much after that," he said, referring to Ryder's dismissal during his Wellington side's season-ending loss earlier in the day to Canterbury in a limited overs match.

Ryder's mother and girlfriend, who were at his bedside when he woke up, have described the beating as a "heinous crime".

Detective Senior Sergeant Brian Archer said police had watched closed-circuit television footage of the incident and had a "reasonably clear picture of what has taken place".

Ryder has a well-publicised history of alcohol-related trouble and had been drinking before the incident, but Archer said alcohol was not an aggravating factor in the attack.