Johnson, 29, is a former fourth-round pick of the 49ers back in 2014. He played out the final year of his four-year, $2,620,544 contract with the 49ers before signing on with the Seahawks in 2018.
After brief stints with the Bills, Cardinals, Chiefs, and Chargers before returning to the 49ers in 2019. San Francisco re-signed him to a one-year contract last year.
In 2020, Johnson appeared in 14 games for the 49ers and recorded 22 tackles, a sack, and three passes defended.