The 49ers made a procedural move on Friday, releasing defensive lineman Ogbo Okoronkwo to make room for wide receiver Christian Kirk. They made things official Saturday.
The 49ers activated Kirk from injured reserve to the active roster, and they re-signed Okoronkwo to the practice squad. Okoronkwo and linebacker Jalen Graham were elevated from the practice squad for Sunday's game against the Falcons.
The team cut defensive lineman Kevin Givens from the practice squad.
Kirk has spent the season on injured reserve.
He signed a one-year deal with the 49ers in free agency in March and will help Sunday in Mike Evans' absence. The team's top wide receiver was ruled out with Achilles soreness.
Kirk, a second-round pick of the Cardinals in 2018, has 432 receptions for 5,415 yards and 30 touchdowns in eight seasons.
Okoronkwo, 31, has appeared in all six games with one start this season. He has two tackles and a sack.