The sheer presence of those two teams as the best club sides south of Cook Strait has been a shot in the arm for southern football, especially when coupled with Dunedin Technical's presence in the Chatham Cup final.
Christchurch-based Mainland football has been left out in the cold with Soccersouth showing dominating form in league and cup competitions.
That success may also be translated into the New Zealand Football Championship, which starts in November, with Otago aiming to improve on last year's dismal record of two wins in 21 games.
Today's 2pm kick-off will definitely produce a top match between two sides, both aiming to be the inaugural winner of the SIFC.
Caversham has on its side the history of 10 years of domination of Otago football, and the consistent presence of Steve Fleming, voted coach of the year at Soccersouth's awards function last night.
Fleming's squad is a good blend of experience and youthful zing, epitomised by the goal-grabbing talent of Tom Jackson, who shares this year's Golden Boot award.
In a period bereft of true strikers, Jackson has emerged as the most promising front-runner for several years.
He has pace, good technique on the ground and is effective in the air.
Jackson's long throw is a weapon in itself, and he has the X-factor of appearing at the right time and place in front of goal.
Jackson's recent partner in attack is new import Dave Dugdale, whose steadier target-man skills look to complement the youngster's pace and energy.
Moving forward, the red machine has several good passers of the ball.
From deep left, Jeremy Wild can launch long-range switches of play that unbalance the opposition.
Blair Duncan has similar passing skills and, in midfield, Darren Overton cracks the whip with Robbie Deeley and Croyden Wheeler adding unbridled energy.
Rhys Henderson has made the centreback position his own with consistently steady performances, ably supported by Mike Smith who, apart from defending well, has scored several spectacular goals this season.
And in Liam Little, Caversham has a top keeper who travelled with the New Zealand squad to the Olympics.
Roslyn's strengths are more broadly based on a combined effort, with player-coach Terry Boylan a key ingredient in the team shape and strategy.
Sean Brand is another key player, and his award as Soccersouth sportsman of the year is sure to squeeze another few miles out of the industrious Scot.
Back from injury, Mike Eisenhut will also add his match-winning class to Roslyn's effort, and consistent performers such as Jamie Taylor, Tim Mather and Ben Keat form a combative midfield.
Centreback Dave Shaw has improved in every game this season, and his partnership with Liam Dunbar and Boylan, in front of veteran keeper Peter Evans, will try to blunt Caversham's cutting edge.
So far honours are even in SPL results, with Roslyn taking first blood at Tonga Park through goals by Brand and Keat for a 2-1 win.
Caversham gained revenge at Ellis Park stretching out a 4-0 lead before Roslyn climbed back into the match with a late flourish to go down 4-2.
The match is sure to be a showcase of local talent operating under full match pressure and, if Otago United coach Terry Phelan is watching, he may see a few options for his New Zealand Football Championship squad which will start training soon for the competition.
