The former All Blacks and Blues doctor was talking with his family and was in a comfortable state, his family said earlier this week.
However, an Auckland Hospital spokesman confirmed this morning that he was in a stable condition in a ward.
Mayhew collapsed after an exercise class in Auckland on Tuesday and a family spokesperson confirmed he had a cardiac arrest as a result of a heart problem.
The 60-year-old was successfully resuscitated and put in an induced coma in intensive care in North Shore Hospital.
Mayhew, who was on the sidelines for 131 All Black tests, has been the team doctor for the Warriors for most of the past decade. He became an Officer of the NZ Order of Merit for his services to sports medicine in the New Years Honours List.
Among the sportspeople he became close to was late All Blacks superstar Jonah Lomu, who suffered from a kidney disorder that contributed to his death, aged 40, in November.
Mayhew, a pall-bearer at Lomu's Eden Park memorial service, said at the time he always admired Lomu for his courage in pushing on with his rugby career despite serious health setbacks.
Mayhew's family have asked for privacy.
