The San Francisco 49ers announced on Monday that right guard Alex Boone has passed a physical and returned to the team. The 49ers have requested a roster exemption and Boone must be added to the 53-man roster before he can participate in a game. The team also signed cornerback Chance Casey, tackle John Fullington and running back Kendall Gaskins to the practice squad.

Casey originally entered the NFL on May 13, 2013, as an undrafted free agent with the Oakland Raiders. He spent training camp with the Raiders before being signed to the team's practice squad on Sept. 2, 2013, where he spent the remainder of the season. Casey was released by Oakland on Saturday.

Casey, 23, attended Baylor University, where he appeared in 39 games and recorded 161 tackles and three interceptions. He earned All-Big 12 Freshman honors in 2009 and appeared in the 2013 Casino Del Sol College All-Star Game as a senior.

Fullington signed with the Green Bay Packers as an undrafted free agent on May 13, 2014. Following training camp, he was released by the Packers on Saturday.

Fullington, 24, attended Washington State, where he tied a program record with 43 consecutive starts. As a senior, he earned Pac-12 All-Academic Second-Team honors and was presented WSU's Mike Utley Award, given to the team's top offensive lineman.

Gaskins originally signed with the Buffalo Bills on April 29, 2013 as an undrafted free agent. He spent training camp with the Bills, and was released on Aug. 30, 2013. Gaskins was signed to the Tennessee Titans practice squad on Oct. 8 and was later released on Oct. 18. The New York Giants signed him to the team's practice squad on Dec. 17, where he spent the remainder of the season. He was released by the Giants on Saturday.

Gaskins, 24, attended the University of Richmond, where he totaled 605 rushing yards on 148 carries as a senior. He finished his career second in total rushing touchdowns (38) in school history. Gaskins earned First-Team All-Colonial Conference honors in 2010 and 2012.