At the start of the year a team must nominate 25 players for the year and all must fall under the cap. It is against the regulations of the league to name anything less than 25 players for the year.
You cannot name less than that to enure they squeeze under the cap, if you can't fit 25 players then you need to reduce the salaries so you can.
Folkes has simply named his preliminary squad and there are definately 3 more spots up for grabs, but who they will be is the question...
Its a smart way to get those just outside the squad to train the house down in hope of getting picked.