The 49ers signed offensive lineman JP Flynn to a two-year contract, and defensive linemen Will Sutton and Cedric Thornton to one-year deals.
To make room on the roster, San Francisco waived defensive back Don Jones, offensive lineman Jamar McGloster and defensive lineman Blaine Woodson.
Flynn originally signed with the 49ers as an undrafted free agent on May 4, 2017. He was waived by San Francisco after the preseason and signed to the team’s practice squad the following day. Flynn was placed on the practice squad injured reserve list on November 13.
The Bears drafted Sutton in the third round of the 2014 NFL Draft. In three seasons with the Bears, he appeared in 36 games with 18 starts and made 82 tackles and seven pass breakups. He was without a team last season after the Vikings cut him out of the preseason.
Thornton originally signed with the Eagles as an undrafted free agent in 2011. He played five seasons with the Eagles and one each with the Cowboys and Bills. Thornton played 15 games with the Bills last season, with three starts, making 27 tackles and two sacks.