I think Nate's appearance will be predicated on Alex Smith's play to start off the game.
If Alex turns in another horrible performance in the first couple of series -- look for Singletary to leave him in for a little longer than expected.
If he pulls Smith after another lackluster peformance -- and Nate comes in and lights it up -- Singletary will have a full-blown QB controversey on his hands and he knows it.
I don't think the Niners want that. I think the powers that be would perfer to see Alex light it up and cement his hold on the starting job.
But Nate's playing time really does depend on how well Alex plays -- or how badly he plays.
We'll find out Sunday night.