SANTA CLARA — Matthew Judon, a perennial Pro Bowler from 2019-22, is joining a 49ers’ defensive line decimated by injuries this month, including Nick Bosa’s calf injury before Thursday’s practice.

Judon, 34, was signed Monday to the practice squad, having worked out Saturday with three other free agents. Rather than immediately sign any of that quartet, the 49ers promoted Viliami Fehoko Jr. from the practice squad for Sunday’s 36-30 win over Arizona.

Judon has 72 sacks in 145 games over a career spent with the Baltimore Ravens (2016-20), the New England Patriots (2021-23), the Atlanta Falcons (2024) and then the Miami Dolphins last season before playing for the Buffalo Bills’ Week 18 game.

The 49ers leaned on Keion White, Ogbo Okoronkwo, Khalid Kareem and usual defensive tackle Osa Odighizuwa to play the edges in a multi-faceted front in an 81-snap effort against the Cardinals. Fehoko, a St. Francis High and San Jose State product, played 13 snaps in his NFL debut without a tackle or stat.

Bosa will miss Sunday’s game against the Denver Broncos (2-1) and possibly the following week’s visit to the Seattle Seahawks (2-1).

“Obviously with our situation, hopefully we’ll get him caught up here real fast and he’ll be an option to help us,” coach Kyle Shanahan said Monday on a media conference call.

Defensive end Mykel Williams could start practicing this week for the first time since tearing his right knee’s anterior cruciate ligament in the 49ers’ Nov. 2 win over the Giants at MetLife Stadium. The 49ers would then have three weeks to activate Williams from the Physically Unable To Perform list.

“With all of the injuries piling up over there, I think I can just come in and help until some of those guys get back,” Judon told NFL reporter Arabia Tillery in a video posted Sunday on her social-media X account @ALL32NFL_.

Judon had 5 ½ sacks and started 15 games for the 2024 Falcons that were coached by Raheem Morris, who is in his first season as the 49ers’ defensive coordinator.

“Rah is a big ol’ kid and he loves the game of football and he knows a lot about it,” Judon added. “I feel we didn’t get a long enough stint together. Just his energy and love and passion ofr the game is what I love as well.”