San Francisco placed defensive lineman Tarron Jackson on the Injured Reserve List, two days after he suffered a neck injury in a team practice. In a corresponding transaction, the team signed defensive lineman Jaylon Allen, most recently of the United Football League’s Memphis Showboats, to a one-year contract.

Tarron Jackson has landed on injured reserve two days after being taken off the field on a stretcher with a neck injury.

The 49ers have placed defensive end Tarron Jackson on injured reserve, the team announced on Tuesday. Jackson, 27, had to be taken off the field on a stretcher over the weekend after sustaining a neck injury. He was taken to Stanford Hospital, where he was conscious and had feeling in his extremities.