That leaves the 14 other members of the pre-tournament training squad to attempt to impress in Scotland's two summer Tests against Ireland and Italy.
And while Robinson doesn't have to name his final 30 until after the clash with the Italians on August 20 he has indicated he hopes to have made up his mind following the encounter with Ireland a fortnight earlier.
"I've believe I've got 25 that have booked their places provided they keep showing the same improvements that they've made so far," said Robinson.
"Everybody's got an opportunity to get there and it's challenging every player to not only get into the final 30 but to also want to get into the starting XV. That's the way we've been trying to train, for them to show they want to be part of the starting XV in New Zealand.
"Each day you're able to see players, how they work, their consistency, but also their desire to get in the squad."
The former England boss and Lions assistant is currently putting the Celtic-based players through their paces at Murrayfield - with the English and French-based stars set to join them on July 4 - and he admits it's a process he and they are thoroughly enjoying.
"It's exciting. Everybody's working very hard and the ethic here is very special," added Robinson.
"They're very enthusiastic and that's what I've been pleased about. That's what you want right across the board. I want players that are enthusiastic, players that have that desire and passion and can be consistent and relentless throughout. If we can get this attitude to be relentless in the way we play, it will make a difference to us in New Zealand.
"This is a great opportunity for the players to make real gains in their strength and conditioning but also in their skill development so we've tried to combine the two during the week.
"Every other summer there is a tour, so they can make the biggest difference to their game now. This is why we are trying to push the guys to maximum.
"The guys who finished the season early will play in that first match against Ireland. Others, like Nathan Hines and Kelly Brown who played right up until the end of May will be given that little bit of extra time. They'll be coming into camp late but they've had a tough season last season so it's important they get time to recuperate and work on their strength and conditioning."