The 26-year-old Mullens played in 19 games (16 starts) across three seasons with the 49ers. He initially signed with San Francisco in 2017 as an undrafted free agent out of Southern Miss.
Mullens was tasked with filling in for an injured Jimmy Garoppolo and produced a 5-11 combined record as the 49ers' starter over his three years in the Bay Area. In the 2020 season, Mullens recorded 2,437 yards with 12 touchdowns and 12 interceptions.
To this point, Mullens has recorded 4,714 passing yards with 25 touchdowns and 22 interceptions in his NFL career.
Mullens suffered an elbow injury in the 49ers' Week 15 matchup against the Dallas Cowboys in December. The injury required surgery, and he missed the team's final two games of the year.
Mullens, however, is expected to be fully healthy for the 2021 season.