Henry's team goes into tonight's test against Australia at Eden Park on the back of two successive losses.
Mains said, when contacted by the Otago Daily Times yesterday, ordinary people could not relate to the pressure the All Blacks coach faced.
However, the pressure on Henry was not just about results, but was also about his decision to seek reappointment and the New Zealand Rugby Union's rejection of Robbie Deans, Mains said.
"Pressure is something that all All Blacks coaches have had to face but [Henry], because of the Robbie Deans situation, is under the most pressure any All Blacks coach has been under," Mains said"But he has brought it on himself in applying for the job."
The New Zealand Rugby Union valued players ahead of coaches, when it should be the other way around, Mains said.
He was astonished the All Blacks coaching trio of Henry, Steve Hansen and Wayne Smith had admitted they had been out-coached last week in the side's loss in Sydney, considering it was a relatively simple game plan adopted by the Australians, he said.
But Mains expected a backlash tonight, and said the All Blacks should win - meaning the pressure should also ease.
Another former All Blacks coach, John Hart, agreed Deans' rejection had impacted on the pressure Henry faced.
The All Blacks coaching panel needed be more positive, Hart said.
He believed the home side could win tonight, as long as the tight five played well.
