The June tour by the British and Irish Lions will cut a swathe through the 2013 Super 15 rugby season, disrupting and potentially distracting Australian teams trying to atone for last year's disappointing performances.
Only one Australian club - the 2011 champion Queensland Reds - reached the playoffs of last season's tournament as injuries raised issues of depth and experience which reverberated through Australia's international season.
The Lions tour will severely test the strength of Australian rugby, but the Super Rugby will more thoroughly examine its health, showing whether it can continue to support five clubs without too heavily diluting its talent.
Wallabies coach Robbie Deans said the expansion of Super rugby through the addition of the Western Force in 2006 and the Melbourne Rebels in 2011 had tested Australian rugby's depth and he acknowledged an impact on the national team.
"Clearly with two new franchises in recent times we've spread the playing group," he said. "It's created a young profile.
"We've suffered a little bit off the back of that because we lack training age, but we're coming through that now. I think we'll start to see that this year in Super rugby.
"Ideally, every franchise will thrive, and the national program, and we'll all get the benefit of it."
The Reds had become the basis of the Wallabies team after their 2011 Super 15 victory but experienced a crushing injury toll during 2012 - the loss of players such as James Horwill, Will Genia, Quade Cooper and Digby Ioane - which impacted on their championships hopes and, eventually, on the Wallabies
The Reds struggled throughout the season and owed their place in the playoffs to the tournament's conference system which requires at least one team from Australia, New Zealand and South Africa to play in post-season competition. Without that proviso and on the strength of its 58 championship points, the Reds wouldn't have qualified for the six-team playoffs.
Of the other Australian teams, the ACT Brumbies finished seventh, the New South Wales Waratahs 10th, the Rebels 13th and the Force 14th. New Zealand, in contrast, had three teams in the playoffs and South Africa had two.
Substantial changes within the Australian teams since last season hold out some hope of refreshment. The Reds, Waratahs and Force have new coaches while the movement of players has strengthened some squads at the expense of others.
Richard Graham will now coach the Reds as championship-winning coach Ewen McKenzie moves into a management role. Michael Chieka has taken over as Waratahs coach, displacing Michael Foley who will now coach the Force.
Those coaches will have to nurse their teams through a season which will be fractured by the three-test Lions series and disrupted by the consequent calls on their international players. The 2013 season will start this weekend with a round featuring only Australian teams; one of two such rounds inserted in the season to create space in June - when Australian teams will become inactive - to accommodate the Lions tour.
Deans said the Lions visit will benefit all Australian teams, which will individually play the tourists ahead of test matches on June 22, June 29 and July 6.
"A large number of players will get to play an international," Deans said. "You look at any Lions series ... and players emerge from that. They respond to that opportunity.
"I've got no doubt there will be players who will emerge this year."
New Zealand and South African clubs will not be without their issues in 2013. In South Africa, the advent of a new franchise - the Cape-based Southern Kings who take the place of the under-performing Johannesburg-based Lions - will be keenly reviewed.
The omens for the Kings have not been good and their pre-season results included a 41-31 loss to the Lions. But lock Darron Neil said critics were premature in writing off his unproven side.
"There's an unbelievable vibe in the Eastern Cape," Neil said. "A lot of people are skeptical, so it's for us to show they needn't be. There are certainly things we need to work on, but I don't believe they're things we can't fix."
The extraordinarily talented former Sharks and Stormers loose forward Luke Watson will captain the Kings in their debut season while they will be coached by former Canterbury Crusaders hooker Matt Sexton. The franchise draws its players in the first instance from three provincial unions, none of which have recently had the strength to qualify for South Africa's premier Currie Cup competition.
The expectation in South Africa is that they will simply supplant the Lions - last-placed in 2012 - at the foot of the championships table.
The Stormers were the best-performed South African team during last year's regular season, finishing in first place before losing to the Sharks in the semifinals. Coach Allister Coetzee said teams needed a big squad to sustain form into the post-season.
"Depth is vital," he said. "That's why we try to grow a bigger squad.
"It's important to play your best players at the back end of the competition and have the strongest side possible to play in playoffs."
In New Zealand, there will be interest in seeing whether the Waikato Chiefs can build on last year's championships success or whether that was the result of a fortuitous alignment of stars.
"I think the biggest thing we got right (last season) was selection," coach Dave Rennie said. "The Chiefs have traditionally had a lot of rock stars but probably lacked a lot of workers.
"We targeted a lot of guys with a big work ethic and that really worked for us, we reckon."
The Chiefs retain their strength of last season, when they became the first New Zealand team to win a Super rugby title since 2008, when the Crusaders claimed their seventh championships.
The Crusaders hope to repair that long omission this season, though they will face the first half of the season without All Blacks captain Richie McCaw, who is taking a break from rugby. The Highlanders are stronger than last season with the acquisition of players such as current All Blacks Andrew Hore and Ma'a Nonu and ex-All Blacks lock Brad Thorn.
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