There was a play, I think in the 2nd quarter, when Pierce ran out of bounds. That seemed strange enough to me because his whole mindset is usually to plow into people and get a few more yards. After that play, he asked out and then Burkhead came in for the rest of that drive (iirc.) That worried me. I was afraid Pierce had hurt himself on that run or something. But he came back and looked fine.
But then, like you said, in the 4th, they seemed to go into 3rd down back mode and pull Pierce. And that worries me. I hope he wasn't playing through something in the 3rd quarter and then they pulled him to bubble-wrap him.
With that said, Dare was looking pretty good. I'd like to see him getting more touches when the game is still on the line... but only if Pierce wants a breather.