Will be a lesser standard on the whole, but dont be suprised if there are good players who are making their way back in post injury etc - ie getting back into the swing of it, and those that have been left out of the first's for whatever reason.
just remember to up your game to their level, but dont let yours drop below their level if you know what I mean (If not I'll explain in a PM - only so much room on a page!).
Your level in a "number" is not important- it's your ability to do your job and support the ref as needed - some are excellent refs from the start but the "8 / 7 / 6" puts a preconception in peoples minds. You might have 7 next to your name bit if you show a 5 on the pitch ya de ya.
Enjoy either way and let us know how it goes.