Rams star cornerback Jalen Ramsey expressed his excitement on social media about Weddle's return to the team.
The 37-year-old Weddle retired after the 2019 season, in which he started all 16 games for the Rams. He served as a team captain and was the defensive signal-caller for Los Angeles that year.
Weddle, a six-time Pro Bowl selection and five-time All-Pro choice, has compiled 1,178 total tackles, 29 interceptions, 9.5 sacks, eight forced fumbles and five fumble recoveries over 201 career games.
He spent his first nine NFL seasons with the Los Angeles Chargers, who selected him in the second round of the 2007 draft out of Utah. He later played three seasons with the Baltimore Ravens before joining the Rams in 2019.
Fuller, who was the Rams' defensive signal-caller in 2021, suffered an ankle injury during Sunday's overtime loss to the San Francisco 49ers that will require season-ending surgery. He was placed on injured reserve Wednesday.
The Rams also are dealing with two additional key injuries in their secondary. Safety Taylor Rapp entered the NFL's concussion protocol and cornerback Darious Williams sustained a shoulder injury against the Niners.
In addition to adding Weddle, the Rams signed defensive backs Blake Countess and Sharrod Neasman to their practice squad and safety Jake Gervase to the active roster due to the injury issues.
The NFC West champion Rams are scheduled to host the Arizona Cardinals in the wild-card round Monday night.