I think Hooker, Wing, Fullback and No 12 are the spots where new players might be in contention. All other spots are pretty well reserved right now.
At 12, Mosese Tuipoltu looks to me to be the best of the younger players. Wing I think would likely be Dylan Pietsch. Hooker probably would be Billy Pollard and Fullback, likely to be Max Jorgensen. But that makes it three Rugby Australia Waratahs so please ignore me if that is too much to stomach.
I do really like the look of Flook, but he would seem to be reliant on Ikitau suffering another major injury.
EDIT : I see the locks probably being a mix of Frost, Philip, Swain and Neville. But if any one of them falls through the cracks, Canham would really come under serious consideration.