The team has signed offensive lineman Tim Barnes to a one-year deal and promoted running back Jeremy McNichols to the active roster from the practice squad.
The 49ers have also signed linebacker Boseko Lokombo and cornerback Channing Stribling to the practice squad and released defensive lineman Noble Nwachukwu from the practice squad.
Barnes initially signed with the 49ers on May 2 and spent training camp with the team before being released on September 1. Barnes entered the NFL as an undrafted free agent with the Baltimore Ravens in 2011. He was released by Baltimore that September and then spent time on the St. Louis Rams' practice squad for the remainder of the season. In five seasons with the Rams, he has appeared in 77 games and started 36.
McNichols initially signed to the team's practice squad on September 4. He was drafted out of Boise State by the Tampa Bay Buccaneers in the fifth round of this year's draft. While at Boise State, McNichols appeared in 34 games and started 25 while rushing for 3,205 yards and 44 touchdowns. He also had 103 receptions for 1,089 yards and 11 touchdowns. As a junior in 2016, McNichols rushing for 1,709 yards and 23 touchdowns on 314 carries which earned him Second-Team All-Mountain West honors for the second-consecutive season. He was waived by the Buccaneers on September 2.
Lokombo signed with the Baltimore Ravens on January 31 after spending three seasons (2014-16) with the B.C. Lions of the Canadian Football League. He appeared in 43 games and had 33 tackles while contributing 40 more on special teams. Following his release from the Ravens on September 2, he was signed to the team's practice squad before being released again on September 26. He spent a brief period on the Oakland Raiders practice squad from September 28 until October 10.
Stribling initially signed with the Cleveland Browns as an undrafted rookie free agent on May 4. He was waived on September 1 and was signed to Cleveland's practice squad five days later. After being released on September 19, he spent time on the Indianapolis Colts' practice squad from September 26 until November 6.
Mostert appeared in each of the 49ers' first 11 games of the season and finished with six carries for 30 yards in addition to eight tackles on special teams. He was initially signed as an undrafted free agent by the Philadelphia Eagles in 2015 and has spent time with six teams in his three NFL seasons. Mostert joined the 49ers practice squad in November of 2016 following his release from the Chicago Bears and was promoted to the active roster on December 31, 2016.
Nwachukwu initially signed with the 49ers as an undrafted free agent on May 4. He was released on September 2 before signing with the practice squad the next day. He was released again on October 11, and then re-signed on October 31.