It could be a case of one from two for the final round of Super Rugby Aotearoa this weekend, with the sold out Blues and Crusaders match at Eden Park heading for cancellation unless Auckland moves from alert Level 3 restrictions.

The rapidly altered Covid-19 landscape forced New Zealand Rugby to explore multiple contingencies on Wednesday as Auckland dealt with its outbreak of four probable cases and subsequent move back to alert Level 3.

While at this stage Saturday's match in Dunedin between the Highlanders and Hurricanes can proceed under restrictions of no more than 100 people at the venue, the highly-anticipated Blues and Crusaders finale will only be played if Auckland moves to alert Level 2 before Sunday.

That prospect is considered highly unlikely.

New Zealand Rugby initially explored the possibility of shifting the Blues and Crusaders match out of Auckland but were then advised otherwise.

"The Government has ruled out the Blues moving out of Auckland under alert Level 3," NZ Rugby head of professional rugby Chris Lendrum said. "Whilst we explored that earlier in the day that's not an option that's open to us. The position is under alert Level 3 is that city is closed down.

"There's many contingencies and options on the table at the moment. The split alert level adds a different complexion to things and it is possible we could have the game in Dunedin but not in Auckland. We'll just see what hand the Government deals us. We've been in lockstep with them the whole way through Covid; we trust their advice, we'll follow it."

New Zealand Rugby is awaiting further Government advice on Friday before beginning the process of potentially refunding tickets from the Blues match but its preference is to conclude Super Rugby Aotearoa this weekend, with the North versus South game at Eden Park scheduled for August 29, and the respective men's and women's provincial competitions due to kickoff from next week.

"We've got other fixtures and competitions flowing off the back of this weekend. The season is pretty jammed up as it is so we're keen to get these games played."

Lendrum conceded the Blues, and New Zealand Rugby as a 40 per cent shareholder in the franchise, would take a serious financial hit if Sunday's match against the Crusaders could not be played after all 43,236 tickets were sold.

Even if Auckland moves to alert Level 2 before Sunday restrictions of 100 people would prevent crowds attending.

"Clearly in the case of the Blues it would be significant. A sold out Eden Park brings a large amount of gate revenue with it, and if it's not to be the case rugby, the club and the whole game will have to deal with that.

"If we can't play with a crowd we'd be disappointed by that but the hope is we can still play the games for our fans to watch on the television."

Despite the Crusaders claiming, and damaging, the title in Christchurch last weekend, Lendrum said everyone involved in the game remained determined to play the fixtures if possible. All teams were stood down from training today while NZR assessed its options.

"We've seen the benefits of rugby restarting and what it's done for the mood of the rugby community and country as a whole over the last nine weeks and it'd be great to finish that out.

"The fact the title has already been won hasn't really impacted on our discussions today at all.

"We're in round 10 of this competition. We're confident teams can front off a limited physical training diet this week and I can tell you the Blues themselves are absolutely raring to play regardless of the impact on preparation."

Discussions around whether the latest Covid breakout would affect NZR's plans to stage All Blacks tests, including a Pacific fixture, Bledisloe Cup and Rugby Championship matches, had not yet begun.

"The fact we're moving back up the alert levels isn't helpful but how long we're there for we don't know. We've still got a significant amount of runway in front of us before any All Blacks test matches are played. We'll pause and draw a breath before we can assess any further longer-term impacts."