The 49ers claimed defensive lineman Sheldon Day off waivers from the Jaguars.
The Jaguars selected Day in the fourth round (103rd overall) of the 2016 draft. He appeared in 22 games, with 11 tackles, two sacks and a pass breakup for the Jaguars.
He played in six games and made three tackles and a sack this season before Jacksonville waived him Saturday.
Day appeared in 48 games in his career at Notre Dame, with 141 tackles, 32 tackles for loss, 7.5 sacks and two forced fumbles.