The Bears on Thursday signed linebacker Danny Mason and tackle Garry Williams, waived defensive lineman Marquis Jackson and waived tackle Adrian Bellard with an injury settlement.
Mason returns after spending part of last season on the Bears practice squad. He re-signed with the team Jan. 4 and remained on the roster until being waived May 25. Mason entered the NFL in 2015 as an undrafted free agent with the Broncos, but he did not play in any regular-season games.
Williams appeared in 41 games with 21 starts over five seasons with the Panthers from 2009-14. He played in all 16 games with 11 starts in 2010 before missing the entire 2011 season with a broken ankle. He appeared in 16 games with nine starts in 2012, but tore his ACL in the 2013 season opener. Williams spent last season in the CFL with the Calgary Stampeders.
Jackson, the twin brother of Jaguars defensive lineman Malik Jackson, entered the NFL with the Vikings in 2013 as an undrafted free agent from Portland State but was waived before the regular season. He appeared in two games with the Arena Football League's Portland Thunder in 2014.
Jackson was signed after participating in both the Bears' rookie minicamp and full-squad minicamp on a tryout basis.
Bellard joined the Bears as an undrafted free agent out of Texas State in May. He was injured in Wednesday's practice.