Thornton, 30, joined the 49ers on a free-agent deal in March after spending the 2017 season with the Buffalo Bills. He previously spent the 2016 with the Dallas Cowboys and played five seasons with the Philadelphia Eagles (2011-15). Thornton entered the league in 2011 as an undrafted free agent out of Southern Arkansas and finishes his playing career with 220 tackles, 7.5 sacks, six passes defensed, four fumble recoveries and two forced fumbles.
Jones previously spent two seasons in San Francisco (2016-17) before signing a free-agent deal with the New York Jets in June, but was released less than two weeks later. Jones entered the league in 2013 as a sixth-round pick with the Houston Texans, and has spent time with the Tampa Bay Buccaneers, New England Patriots and Miami Dolphins.