Connolly has earmarked four rookies to make the tour - Sam Cordingley, Josh Valentine, Brett Sheehan and 19-year-old Josh Holmes.
However, Connolly is harbouring concerns over the fitness of three of the four number nines.
Cordingley is sidelined with a foot injury, Valentine has a knee problem and Sheehan has a fractured eye-socket, so Connolly has not ruled out needing Gregan to be available for the tour.
"We don't know where [Sam] Cordingley's future lies with this foot injury and [Josh] Valentine is yet to come back from his knee injury," Connolly said.
"George, the decision at the moment is he may not tour but we haven't confirmed that yet.
"The Australian Provincial Championship (to be held in September) will be very important for some players. There's a couple of back-row spots up for grabs and a couple in the outside-backs."
Meanwhile, Gregan is fully focused on next weekend's clash against the Springboks, which concludes the 2006 Tri-Nations series.
Australia beat South Africa 21-20 in Sydney three weeks ago, but the match was a dour affair dominated by poor territorial kicking and dropped ball.
"I think we'll look to use the ball a bit more than we did last time, but we'll play what we need to get a good result," Gregan said.
"And a fair bit of that is going to be getting the balance right between playing field position - and the way football is being played now you want to play at that end of the field - but also when you get the opportunities to fire a shot you use those opportunities as well as you can."