Jesse Ryder has been "interacting with his family" as police charged a second man about the incident which left the New Zealand cricketer in an induced coma in hospital.

Ryder, the 28-year-old Wellington all-rounder, was today "stable" in Christchurch Hospital having been admitted in the early hours of yesterday morning after suffering multiple injuries, including a fractured skull, in the attack.

Police investigating the incident today confirmed two men - a 20-year-old and a 37-year-old - would appear in court on April 4 after being charged with assault.

Ryder today remained in an induced coma, but had responded to his family and doctors, according to New Zealand Cricket Players' Association chief executive Heath Mills.

Mills said: "Jesse is in a stable condition in intensive care.

"He has been responsive and has been interacting with his family and the medical team.

"Jesse is still in an induced coma and still needing support with breathing following an injury to his lungs.

"In terms of a head injury, it cannot be fully determined at this stage what the effects of a knock to Jesse's head are.

"We will know more once he comes out of the coma."

Police said yesterday Ryder was involved in an altercation with a group of people outside Aikmans bar in the Christchurch suburb of Merivale shortly after 12.30am local time, and was then assaulted by one of the group who followed him towards the car park of a nearby McDonald's.

After reviewing CCTV footage, police now believe only two people were involved in the initial incident.

Having earlier confirmed a 20-year-old man had been charged, police today released a statement saying: "Police have interviewed a 37-year-old male in relation to his involvement in an altercation with cricketer Jesse Ryder.

"This person has been arrested and charged with assault and will appear in Christchurch District Court on Thursday 4 April."

Detective senior sergeant Brian Archer earlier confirmed the 20-year-old was charged in relation to "the initial incident" and that there was a "family connection" between the two.

According to Ryder's agent, Aaron Klee, Ryder had given doctors a "thumbs up".

He added on "They are assessing his coma at the moment and when the right time will be to bring him out of the coma."

Ryder, a controversial figure whose career has been plagued by off-field incidents, is on an indefinite break from international cricket and has not played for New Zealand since February last year.

He has admitted in the past that alcohol has contributed to his off-field problems and it was confirmed that he was drinking with his Wellington team-mates in the bar before he was attacked.

Former New Zealand pace bowler Iain O'Brien said: "He's the kind of guy that always will have a drink.

"When he is off the stuff he's a wonderful, wonderful man - he's one of the funniest guys and very jovial - but on the other side of it, when he has been drinking he can certainly suffer the lows."

Ryder has played 18 Tests and 39 one-day internationals for the Black Caps, his last appearance an ODI against South Africa.

He played on Wednesday for the Wellington Firebirds in the major preliminary final against Canterbury Wizards at Hagley Oval and was due to fly out to India this week to compete for the Delhi Daredevils in the Indian Premier League.