I am brining on Friday night.
Would hate to have you freeze a fresh turkey. You don't need to freeze it if you're brining it. If not, then it's a coin toss -- you could freeze it until Friday, or take the risk. If your fridge is kept cold it should be fine until Saturday.
Whoo--maybe close to borderline, but not enough to make me freeze it. If you're worried, consider turning the temperature in your refrigerator down a notch.
I would consider brining it now instead of on Friday to 'preserve' it (the salt in the brine will kill off surface germs), and then removing it from the brine and setting it in the coldest part of the fridge, perhaps in a tray of ice cubes. you should be fine for Saturday, especially if the turkey is slaughtered really recently!