Veteran running back Kerryon Johnson is expected to make his 49ers debut on Sunday night against a familiar opponent.
The 49ers on Saturday activated Johnson from the practice squad (standard elevation) to serve as a reserve against the Green Bay Packers with rookie Elijah Mitchell not expected to be available due to a shoulder injury.
The 49ers placed running back JaMycal Hasty and defensive lineman Kevin Givens on injured reserve with high-ankle sprains. Both players will be out of action for a minimum of three games, as required when going on IR.
Johnson will be available for the 49ers' backfield with the team down four running backs from those they expected to have this season.
Raheem Mostert is out for the season with a knee injury. Jeff Wilson Jr. is expected back in the middle of the season from a knee injury. And Mitchell is listed as doubtful with a shoulder injury. Hasty is out indefinitely.
Rookie Trey Sermon, a third-round draft pick from Ohio State, will be the 49ers' starter Sunday night after clearing through the NFL's return-to-play concussion protocol.
Johnson joins a group of reserves that includes Jacques Patrick, signed off the Cincinnati Bengals practice squad this week, and Trenton Cannon, whom the 49ers claimed off waivers from the Baltimore Ravens last week.
Johnson, 24, played his first three NFL seasons with the Detroit Lions. He appeared in 34 games with 16 starts. He rushed for 1,225 yards and 11 touchdowns on 283 carries for a 4.3-yard average. He also caught 61 passes for 527 yards and three touchdowns.
While playing in the NFC North, he faced the Packers five times. He carried 46 times for 192 yards and four touchdowns against Green Bay.