Chad Rinehart, who had been pegged to replace regular starting right guard Kraig Urbik (high ankle sprain) all week, was a random Friday addition to the injury report, listed as questionable with a calf injury. It seems very logical that his calf has flared up despite the fact that he's active; as such, Brown will start at right guard, Rinehart will play only if necessary, and Buffalo's line looks even scarier now than it did all week.
Brown will still be the primary backup center on the day, as well.
This game is under way, by the way. San Francisco got the ball first, and aided by an early holding call went three-and-out. Leodis McKelvin scored a touchdown on the ensuing punt return, but that play was called back on a Jairus Byrd holding penalty.