The San Francisco 49ers will face a challenging matchup against the Green Bay Packers without key players, as quarterback Brock Purdy and defensive end Nick Bosa have been ruled out due to injuries. Purdy will be replaced by Brandon Allen as the starting quarterback. This injury setback comes at a critical juncture for the 49ers, raising concerns about their prospects for the remainder of the season. Coach Kyle Shanahan acknowledged the impact of these absences, calling it a potentially decisive game. Meanwhile, the Packers may benefit from this injury situation as they prepare to take on a struggling 49ers team.