Tarron Jackson, a defensive end seeking a roster spot with the 49ers, was placed on a backboard and hospitalized after a hard collision during Sunday's practice.

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.