The San Francisco 49ers take on the AFC South's Jacksonville Jaguars at Levi's Stadium on Sunday, Sept. 28 at 1:05 p.m. PDT. The Niners will be without Nick Bosa for the first time this season after he tore the ACL in his right knee. It's not clear who will start at quarterback as Brock Purdy practiced last week but remained out with a toe injury, while backup Mac Jones played well in key moments for a second straight week in a win over Arizona.