Key Points:

Sky TV is set to shed close to a million viewers from its prime time Friday night rugby coverage over the course of this Super 14 rugby tournament.

Last year more than 3 million viewers had tuned in to Friday night matches at this point of the season. This year, that figure is closer to 2.1 million.

Even adjusting the figures to allow for the fact that one fewer Friday night primetime match has been screened this season, it is a drop of more than 22 per cent.

This season's most-watched Super 14 match - a round five clash between the Blues and Highlanders that attracted 269,400 viewers - wouldn't have rated in the top 10 most-watched games in New Zealand last season.

And the news gets worse for Sky: the All Blacks might be back but the viewers aren't.

The phased reintroduction of the 22 All Blacks stars who were kept out of the first seven rounds of the Super 14 in order to train for the world cup, seems to have had little effect on viewer numbers. Round eight's Friday night figure was 32 per cent down on the previous year, with both matches featuring the large-market Blues playing at home.

Even fewer viewers tuned in the following week, with a 41 per cent drop off from the previous season's corresponding Friday night encounter.

Easter Friday's traditionally low viewing figures were on a par with the previous season and there was a slight bounce back last weekend when 252,700 tuned in to watch the Hurricanes defeat the Cheetahs.

That figure was the third-highest Friday night viewership this year but it was still down 13 per cent on last season when the Chiefs played the Cheetahs.

The tune-out could have ramifications for the NZRFU, which was last year threatened with legal action by broadcasting giant News Limited - an owner of Sky TV - should the ratings of its flagship rugby competition take a dive following the withdrawal of the 22 All Blacks.

News Limited director of corporate affairs Greg Baxter had not responded to the Herald's request for an interview by press time but he was quoted in a Sunday newspaper story this month as saying it was "clear" the resting of the 22 All Blacks had affected public interest in the competition. Mr Baxter said in the article the company had yet to take a "definitive view" on what action it might take.

The NZRFU declined to comment on the matter.

Sky TV director of communications Tony O'Brien said the Super 14 continued to be a valuable subscription driver.

"There's no doubt that the early start to the season, the success of the Black Caps and the [All Blacks] reconditioning has probably hurt viewership for the first part of the season but the most valuable aspect to us of the Super 14 is that it's a subscription driver and it continues to be very valuable to us."

Subscriptions were up through February but he had not seen more recent figures, he said.

Asked if Sky was at all alarmed about the drop-off in viewership of one of its premier products, Mr O'Brien repeated his earlier statement that the competition continued to be a "valuable subscription tool".

He declined to discuss whether the ratings had hurt the company's bottom line due to a drop in the value of advertising surrounding matches, but media commentator Russell Brown said such a scenario was likely.

Sky was paying the price for diluting the quality of their product by expanding the competition from 12 to 14 teams and for over-exposing it by showing too much rugby, Brown said.

"I think you can put some of it down to the All Blacks not being there for those early rounds but I don't know that you can put all of it down to it," he said.

"You've got to wonder if there is just too much rugby and whether the quality is not good enough either. Especially when you have got the Australian teams going so badly - they are just unwatchable."

Sky's advertising revenue would have taken a hit but the real issue was whether subscription numbers had dropped, he said.

"I know Sky does see a fall-off in subscriptions every summer because people sign off once the rugby's over, whether that has happened and people just haven't come back I am not sure."