This means Sam Darnold will get his first start as a 49er, lowering the offensive expectations for San Fran across the board. This line movement isn't surprising considering the 49ers droppings two straight games and the likelihood of starting quarterback Brock Purdy missing this game due to being in the concussion protocol. The total for the Week 8 game against Cincinnati has also dropped, going from 46 last week to 43.5 as of Friday, October 27.
Compared to the lookahead lines from last week, the 49ers spread has dropped two full points from -6 to -4, still in favor of San Francisco.