Green Bay Packers lose linebacker Krys Barnes to a concussion against San Francisco, Niners secondary also depleted

The Packers lost inside linebacker Krys Barnes early in their Sunday night battle with the San Francisco 49ers to a concussion, and he won't be back.
Barnes was shaken up tackling 49ers receiver Brandon Aiyuk in the first half. Barnes, who became an immediate starter last year as an undrafted free-agent rookie out of UCLA, was replaced on the field primarily by Ty Summers.
The San Francisco 49ers, meanwhile, lost defensive back Josh Norman for the game with a chest injury in the first half. The 10-year veteran and former All-Pro cornerback just signed with San Francisco on Sept. 6 but played 97% of snaps in a Week 2 win over Philadelphia.
With K'Waun Williams also questionable to return in the secondary for San Francisco after he suffered a calf injury, the 49ers are increasingly thin at cornerback.
More:Green Bay Packers-San Francisco 49ers live game blog with Tom Silverstein