Wellington - Puffed-out referees need to make sure they are in shape to keep up with play in modern Test rugby, All Blacks assistant coach Wayne Smith said on Wednesday.
The All Blacks in particular were keeping the ball in play longer rather than kicking for touch, reducing the number of set pieces and opportunities for referees to catch their breath, he added.
"The ball in play is around 40 minutes in the Test matches this year because of the way we're playing," Smith told reporters in Wellington.
"If you talk to our tight forwards, they'll talk about how the game has changed, markedly, because of the amount of running they have to do.
"Referees are going to need to make sure they're up there fitness-wise."
Smith's comments followed the All Blacks' 32-12 victory over the Springboks in Auckland, where 46-year-old referee Alan Lewis appeared to struggle to keep up with play at times and drew media criticism for missing a number of incidents.
Lewis's struggles prompted New Zealand coach Graham Henry to renew his call for a second match referee to be made available to relieve the first after a period of time.
"It might be after 50-55 minutes. So you have two quality refs who can keep up with the play," Henry told local media this week.
Smith said the increased pace had rejuvenated the game as a spectacle after last season was marked by territory-based kicking games. "I think the game is going in the direction people want it to go in. There can't be too many complaints around from people watching the game at the moment," he said.