The San Francisco 49ers will be without free-agent acquisition Jerick McKinnon after the running back tore his ACL during workouts on Saturday.


Preliminary reports indicated the injury was serious, and an MRI confirmed it.

Just a few months ago, the 49ers made McKinnon one of the highest-paid running backs in the league in free agency.

Now the team will have to lean on veteran pickup Alfred Morris, who only recently came on board due to a minor rash of injuries at the position. Second-year back Matt Breida will also be a featured player and look to build upon a solid first year.