But McCafferty maintains that a strong league will result in a strong England team with the overseas players raising standards and helping the development of the new generation of England players.
He also produced figures showing that the ratio of English players over imports is virtually the same as it was 10 years ago.
"The numbers aren't changing," McCafferty said. "England still has a huge pool of talent.
"The standard is going up but the numbers are the same and we would like to keep it that way.
"We make no bones about wanting to attract the world's best players at the peak of their careers to make our league that much more attractive and the shift we have seen this season is from some journeyman overseas players to some real star players."
Irish, Scottish and Welsh players are included in the 36 per cent of "foreign" players in the Premiership. The ratio of British to overseas players is 77-23.
"We believe the balance is about right," said McCafferty who highlighted the emergence of young players already capped by England, including Bath prop Matt Stevens, Leicester centre Dan Hipkiss, Newcastle duo Mathew Tait and Toby Flood, the Wasps back row pair of James Haskell and Tom Rees and Gloucester backs Olly Morgan and Anthony Allen.
"We relish the obligation of providing a conveyor belt of English talent as far as the national side is concerned.
"As we approach that challenge we do have to balance the needs of our stakeholders. Clubs are clearly interested in success, as are supporters, and that comes with a mix of both English and overseas talent.
"Finding that balance is absolutely crucial and there is a generation of English talent coming through that can be world class, given the right development and the right progress."
McCafferty believes that the way forward globally for rugby is for the game to raise the standards of leagues in other countries to the level of the Guinness Premiership and France's Top 14.
Premier Rugby will be pushing that philosophy at this month's International Rugby Board conference.
"One of our pleas to the IRB is that they need to strengthen and protect other leagues in both the northern and southern hemispheres," McCafferty added.
"England and France provided a major number of players to the World Cup squads of emerging countries like Samoa and Fiji along with Argentina, who have well and truly emerged.
"We think part of that solution is making sure that some of the other leagues around the hemispheres are protected and that structures are built in to feed the international game."