Sanu spent the remainder of the season with the Detroit Lions.
The Cincinnati Bengals made Sanu a third-round selection out of Rutgers in 2012. He registered 17 receptions for 187 yards with a touchdown through 10 games last season between the 49ers and Lions. That includes his one catch for nine yards in three game appearances with San Francisco.
Sanu, 31, has caught 420 passes for 4,694 yards with 27 touchdowns through his nine NFL seasons. He is entering his 10th NFL season, which also included stints with the Atlanta Falcons and New England Patriots.
Before his time in San Francisco, Kyle Shanahan previously worked with Sanu in Atlanta when the 49ers head coach was the offensive coordinator there.
H/t to Patrick Tulini for the find.