The San Francisco 49ers will be without Elijah Mitchell for 6-8 weeks because of a knee injury.
Mitchell left Sunday's win over the New Orleans Saints with the injury. The Niners originally thought the running back had an MCL sprain that would sideline him for just 2-4 weeks.
"It wasn't the news we were looking for," Kyle Shanahan said.
Mitchell, who set a franchise rookie record with 963 yards rushing last season, only returned from an injured reserve stint on Nov. 12. He injured his knee in the season opener and missed seven games.
"He's pretty disappointed," Shanahan said. "Everyone knows how good Elijah's been, how hard he's worked to get back from his last one and how good he's been playing since he came back. To be right back there, I know he was real down on it. He's had some real bad luck. He got rolled up on and it was a bad position for him to be in."