Johnson joined the San Francisco 49ers in December and played 22 offensive snaps in two regular season games, going 1-for-2 for 10 yards and carrying twice for three yards.
After Brock Purdy's PCL injury on the Niners' first offensive series,
the 37-year-old played 23 offensive snaps in the NFC Championship Game defeat to the Philadelphia Eagles.
Johnson was concussed after 7-for-13 for 74 yards and two carries for two yards.
If healthy, Baltimore's former fifth-round pick won't play much in 2023.
In late April, former MVP Lamar Jackson inked a five-year, $260 million contract, with 2022 Pro Bowler Tyler Huntley expected as backup.