This is the first time he'll prepare for a St. Louis team without Steven Jackson.
The bruising running back has now been replaced by the tandem of Daryl Richardson and Isaiah Pead.
"Steven Jackson was there throughout my career," Brown said. "Now they have a quicker, faster scatback (in Richardson). They're doing great job with zone reads and stretching the field. Everybody's going to be tested, everybody's going to be challenged this game and everyone has to win their one-on-one battles."
The Rams also boast several new wide receivers, including 2013 first-round draft pick Tavon Austin. It's a very quick receiving corps that presents several challenges, according to Brown.
"Explosive offensive," Brown said. "Bradford does a great job getting the ball out of his hands, putting it in places where only his receivers can catch the ball. They have speedy receivers, guys that get in and out of their breaks very well."
"The biggest thing is to jump on film as early as possible," Brown said. "Guys have been putting in a lot of extra time watching film, trying to break things down. It's a short week so everything has to push up a little faster than usual."
Though San Francisco has not started the way it would have liked, the players understand that with 13 games remaining in the regular season, there's plenty of time to turn things around.
"It's still early," Brown said. "There's no time to panic. The good thing about this team is we've never been in this situation before. This is really going to determine a lot of guys' character and see where their heart is. We look forward to it, we embrace the pressure, we embrace the scrutiny. At the end of the day, we understand what we have to do."