49ers defensive lineman Arik Armstead broke his hand and needs surgery, coach Kyle Shanahan announced Monday. San Francisco could place Armstead on injured reserve, which would rule him out for at least eight weeks.
“He’s going to need surgery, so it’s going to be some time,” Shanahan said, via Matt Maiocco of NBC Sports Bay Area.
The 49ers also will play without defensive end Aaron Lynch on Sunday against the Cowboys. They list Lynch week to week with a calf strain.
Although they will see the return of linebacker/defensive end Dekoda Watson from a groin strain, the 49ers could make a roster move to add a defensive lineman.
“The more guys you lose, the less you like that depth,” Shanahan said. “Losing Arik, which could be some time, we’ll have to discuss IR. We have to do that over the next couple of days. We know we’re going to have Lynch out, too, for at least a week or most likely more. That takes away two guys who were helping.”
Armstead, the 49ers’ first-round pick in 2015, has 50 tackles and six sacks in 30 career games, including 16 tackles and 1.5 sacks this season.