Regular matches between club sides across the world will happen "sooner or later", says outgoing Premiership Rugby boss Mark McCafferty.
Private equity firm CVC have already completed a 27% purchase of the English league and are in talks with the Pro 14 about buying a stake in that league.
Cross-hemisphere matches could form part of CVC's vision for the future.
"Eventually I'm sure there will be club games on a reasonably regular basis between the hemispheres," he said.
- CVC buys £200m minority stake in Premiership Rugby
- £5bn offer for Nations Championship
- McCafferty urges unity over rugby future
He added to BBC Radio 5 Live: "That is going to happen sooner or later because I still think the big unanswered question in rugby is 'which is the best club side in the world?' No-one answers that because they don't ever play.
"That is one of the things I would love to see happen at some point."
McCafferty will work with CVC as an adviser after he stands down from Premiership Rugby after 14 years as chief executive.
He says he hopes he can help get ambitious new proposals over the line, although he has warned against adding more matches to rugby's crowded calendar.
"It's not necessarily on the radar at the moment but these things have a natural momentum sometimes," he added.
"Clubs are getting bigger, the brands are getting bigger and they want to play on a global stage.
"These things sometimes just need the right time and moment and the right push and momentum - hopefully I will be able to help with some of those things."