The 49ers signed defensive back Antone Exum Jr. They placed swing tackle Garry Gilliam on injured reserve in a corresponding move.
Gilliam injured his knee in the Oct. 29 loss to the Eagles. He started at right tackle that game, with Trent Brown out with a concussion.
Gilliam appeared in the team’s first eight games.
The Vikings drafted Exum in the sixth round in 2014. He appeared in 27 games, with two starts, making 18 tackles on defense and 13 more on special teams. Exum spent 2016 on injured reserve, and the Vikings waived him Sept. 16, 2017.