The 49ers' offense is a shell of what it could be with Brock Purdy dealing with a sore arm, Pro Bowl left tackle Trent Williams out, reliable wide receiver Brandon Aiyuk out and their two top running backs, Christian McCaffrey and Jordan Mason, both sidelined, too.

Chicago's defense is respectable. The Bears held the Packers, Commanders and Rams all under 21 points. They also yielded just 23 points to the Lions, who lead the NFL in scoring at 32.1 points a game. 

The Bears haven't broken the 20-point barrier in any of their five road games. Chicago is averaging 14.6 points in its five road contests. The Bears also might be down their top receiver as D.J. Moore is questionable. 

Chicago just fired Matt Eberflus. Good for them. But they named Thomas Brown interim head coach. Brown had just recently been elevated to offensive coordinator. Now he's responsible for the entire team. So details to Chicago's offense may get neglected this week, especially on a long road trip. 

The 49ers are going to play with maximum intensity. They will be conservative, too, relying on third-string rookie running back Isaac Guerendo. 
So I see a low-scoring game.