The Bears (3-8) have lost four straight games and six of eight since a Week 3 overtime win over the Pittsburgh Steelers at Soldier Field. They're 2-4 at home this season.
The 49ers (1-10) possess the NFL's second worst record behind the Cleveland Browns (0-11). San Francisco opened 0-9 before recording its first win of the season, 31-21, over the New York Giants Nov. 12. The 49ers then lost to the Seattle Seahawks 24-13 last weekend.
Quarterback Jimmy Garoppolo will make his first start as a member of the 49ers Sunday against the Bears.