The Los Angeles Chargers placed running back Gus Edwards and cornerback Asante Samuel Jr. on injured reserve. They will miss at least the next four games.
Samuel's designation came as a significant surprise. He practiced all week except Friday, when he was ruled out with a shoulder injury. Coach Jim Harbaugh said Friday that the injury didn't happen at practice.
Samuel suffered a shoulder injury in practice ahead of the Chargers' Week 1 game against the Las Vegas Raiders and was questionable for that game but played and hadn't missed any time since.
"We've gone over this many times, right? I'm not qualified to go into the medical details of it," Harbaugh said when asked about Samuel's injury Friday.
Samuel's injury is a blow to an already hobbled secondary. The Chargers will also be without starting nickel cornerback Ja'Sir Taylor (fibula) for Sunday's game against the Broncos.
With Taylor and Samuel out, rookie cornerbacks Cam Hart and Tarheeb Still will likely see increased roles. Third-year cornerback Deane Leonard, who is questionable with a hamstring injury for Sunday, would likely be next in line at outside cornerback with Samuel out.
Cornerback Kristian Fulton, who starts opposite of Samuel, is also questionable with a knee injury for Sunday.
Edwards missed practice this week with an ankle injury but was briefly on the field with a trainer at practice Friday. Harbaugh said he expects rookie running back Kimani Vidal to be active for the first time this season for Sunday's game.
Running back Hassan Haskins, signed by the Chargers after training camp, will likely see an increased role behind running back J.K. Dobbins.
The Chargers also activated LB Nick Niemann from injured reserve, signed safety Tony Jefferson to the active roster and elevated cornerback Dicaprio Bootle from the practice squad for Sunday's game against the Denver Broncos.