Baldwin, 24, was acquired via trade from the Kansas City Chiefs last August in exchange for fellow first-round wide receiver A.J. Jenkins. Kansas City selected Baldwin with the 26th overall pick in the 2011 NFL draft.
Baldwin had three catches in seven games last season and has just 44 catches for 607 yards and two touchdowns in three seasons.
The 49ers also announced they claimed wide receiver L'Damian Washington off waivers from the Dallas Cowboys. Washington is an undrafted rookie free agent out of Missouri.
- Scooby Axson