If you have three QBs competing for the starting spot, is there any way you wouldn't say this? Let's see what happens if you declare a starter right now:
1. You discourage the other two that you don't expect to use but might have to if there is an injury
2. You (might) let the starter's guard down a little
3. You help opponents prepare for you
I read anything that starts with "at this point" as "mind your own business".