The 49ers have been steadily tweaking their roster since hiring General Manager John Lynch and coach Kyle Shanahan earlier this year and the process continued on Thursday.
The team announced that defensive back Will Davis has been signed to the 90-man roster. Wide receiver Rashad Ross, who signed to a future contract in January, was dropped to make room.
Davis entered the league as a third-round pick of the Dolphins in 2013 and saw action in 15 games before tearing his ACL during the 2014 season. He was traded to the Ravens early in the 2015 season and tore his ACL again before returning for three games last year.
Davis is listed as a cornerback by the 49ers and played there in Miami, but also has experience at safety from his time in Baltimore.